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  • How do private BitTorrent trackers monitor how much users upload/download?

    - by Jon-Eric
    From Wikipedia: Most private trackers monitor how much users upload or download, and in most situations, enforce a minimum upload-to-download ratio. How exactly can a tracker figure out how much data was uploaded and downloaded by each user? My understanding is that a BitTorrent tracker is merely a registry of users that are currently downloading/seeding and that peers, once connected, transfer data directly. So I wouldn't think that the tracker would know anything about the amount of data transferred, much less, where it came from.

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  • Do I still need to send the "Expires" header, or can I assume that web caches understand "Cache-Cont

    - by chris_l
    I want to reduce the overhead caused by HTTP headers to a minimum, so I'd like to avoid the "Expires" header, and use "Cache-Control" only - or maybe the other way around (I'm planning to send very short HTTP responses to browsers, so the answer to this question doesn't fully apply here: My headers account for a significant percentage). AFAIK, the "Cache-Control" header was standardized in HTTP 1.1, but are there still web caches/proxies, that don't understand it? Note: This is a sub-question to my stackoverflow (bounty) question

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  • how to get rid of certificate error: navigation blocked in ie8

    - by Radek
    when I access our intranet via https I get this "certificate error: navigation blocked" error in IE8 on Windows XP SP3. I can click Continue to this website (not recommended). but I use IE for automation testing so I have to avoid these extra clicks. Any idea? I tried setting “Turn off the Security Settings Check feature” to enabled. setting "Display Mixed Content" to enabled lowering security levels to minimum adding the web server address to trusted zone

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  • Verizon FiOS Speed concerns

    - by Josh K
    I'm working on getting a separate internet connection to run out and I was looking into available options. FiOS claims to offer 25Mb up / 25 Mb down as a maximum rate. Do they have listed minimum rates? Is there anything with fiber I should be concerned about? Special hardware, special routers, availability concerns?

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  • How to determine where debian package was sourced

    - by user169309
    How would I trace out which archive(s) in the sources.list a given installed deb package was or (could be) sourced from? I understand that the same package may be indexed by multiple archives. Does "aptitude" log any of this type of information when its installing packages? My aim is to pare down my current sources.list to the minimum set of archives needed to maintain the current set of installed packages.

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  • how to optimize apache on web-server

    - by Prakash
    how can I optimize the server with following configuration. It takes too much time to load a page. IBM X3200 M3 Server - 1 Intel Xeon Processor with 4 GB Ram Below is my current configuration for apache: Start Servers: 5 (Default) Minimum Spare Servers: 10 Maximum Spare Servers: 20 Server Limit: 500 Max Clients: 500 Max Requests Per Child: 10000 (Default) Keep-Alive: On Keep-Alive Timeout: 5 Max Keep-Alive Requests: 100 Timeout: 200

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  • PES 2012 results in a Nvidia error on Dell N5110 regarding System Requirements?

    - by ???? ???????
    I bought laptop Dell N5110 and installed PES 2012. Nvidia graphics card has 1GB RAM, but when I try to run game message appears that there is just 128MB graphics memory. Here is the message: Warning :Your computer does not meet the Minimum System Requirements to run this software.As a result, you may experience errors during operation.Your Video Card does not meet the required specifications.(GPU:VRAM 128MB) What could be the problem?

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  • Reach self hosted server from LAN

    - by Freefri
    I have a self hosted server with Apache2 pointed with the domain example.com. I have also some virtual servers www.example.com, cloud.examle.com, etc. This server is in my LAN, and when I try to acces to my server within the lan throw www.examle.com y get my router's configuration page. From outside the LAN www.example.com and cloud.examle.com works properly. From inside the LAN 192.168.1.33 (server internal IP) shows the default webpage (www.examle.com), but I can not get cloud.examle.com I also have a LAN name server in 192.168.1.33 with bind9. I set up my gateway 192.168.1.1 with my LAN-NS as primary NS I solve this problem creating a new dns zone in the NS. This are my config files: ;ZONE-1 $ORIGIN . $TTL 86400 ; 1 day home.lan. IN SOA server.home.lan. hostmaster.home.lan. ( 2008080901 ; serial 8H ; refresh 4H ; retry 4W ; expire 1D ; minimum ) home.lan. IN NS server.home.lan. $ORIGIN home.lan. ; Set the address for localhost.home.lan localhost IN A 127.0.0.1 router IN A 192.168.1.1 server IN A 192.168.1.33 mypc IN A 192.168.1.132 ;ZONE-2 $ORIGIN . $TTL 86400 ; 1 day example.com. IN SOA www.example.com hostmaster.home.lan. ( 2008080902 ; serial 8H ; refresh 4H ; retry 4W ; expire 1D ; minimum ) example.com. IN NS 192.168.1.33 $ORIGIN examle.com. localhost IN A 127.0.0.1 www IN A 192.168.1.33 cloud IN A 192.168.1.33 My DNS and my names are working properly now My question are: What do you think about my solution? Can I change the A zone with CNAME to server.home.lan (this is the domain in the LAN to the server)? How can I set a default IP for all my whatever.example.com?

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  • "Can't Connect to Server" from 2nd virtual host on VPS

    - by chaoskreator
    I'm using Debian 7 Wheezy and Apache 2.2.22, and I'm setting up Virtual Hosts for a number of websites on my VPS. I've successfully configured the VirtualHost directives for one of the sites, but the second one continually gives "Problem Loading Page" in Firefox. I've run configtest and it has verified all my syntax is correct, and I've checked all the permissions. Everything on the 2nd domain is pretty much copy/pasted from the first, so I'm not sure what the issue is, as there are no entries into /var/log/apache2/error.log other than where I have reloaded the configurations: /# cat /var/log/apache2/error.log [Thu May 29 01:19:00 2014] [notice] Graceful restart requested, doing restart [Thu May 29 01:19:00 2014] [info] Init: Seeding PRNG with 656 bytes of entropy [Thu May 29 01:19:00 2014] [info] Init: Generating temporary RSA private keys (512/1024 bits) [Thu May 29 01:19:00 2014] [info] Init: Generating temporary DH parameters (512/1024 bits) [Thu May 29 01:19:00 2014] [debug] ssl_scache_shmcb.c(253): shmcb_init allocated 512000 bytes of shared memory [Thu May 29 01:19:00 2014] [debug] ssl_scache_shmcb.c(272): for 511920 bytes (512000 including header), recommending 32 subcaches, 133 indexes each [Thu May 29 01:19:00 2014] [debug] ssl_scache_shmcb.c(306): shmcb_init_memory choices follow [Thu May 29 01:19:00 2014] [debug] ssl_scache_shmcb.c(308): subcache_num = 32 [Thu May 29 01:19:00 2014] [debug] ssl_scache_shmcb.c(310): subcache_size = 15992 [Thu May 29 01:19:00 2014] [debug] ssl_scache_shmcb.c(312): subcache_data_offset = 3208 [Thu May 29 01:19:00 2014] [debug] ssl_scache_shmcb.c(314): subcache_data_size = 12784 [Thu May 29 01:19:00 2014] [debug] ssl_scache_shmcb.c(316): index_num = 133 [Thu May 29 01:19:00 2014] [info] Shared memory session cache initialised [Thu May 29 01:19:00 2014] [info] Init: Initializing (virtual) servers for SSL [Thu May 29 01:19:00 2014] [info] mod_ssl/2.2.22 compiled against Server: Apache/2.2.22, Library: OpenSSL/1.0.1e [Thu May 29 01:19:00 2014] [notice] Apache/2.2.22 (Debian) PHP/5.4.4-14+deb7u9 mod_ssl/2.2.22 OpenSSL/1.0.1e mod_perl/2.0.7 Perl/v5.14.2 configured -- resuming normal operations [Thu May 29 01:19:00 2014] [info] Server built: Mar 4 2013 22:05:16 [Thu May 29 01:19:00 2014] [debug] prefork.c(1023): AcceptMutex: sysvsem (default: sysvsem) I've ensured to enable each vhost with a2ensite {sitename.conf} with no errors there, either. Below are the contents of the configuration files... /etc/apache2/apache2.conf # Global configuration # LockFile ${APACHE_LOCK_DIR}/accept.lock PidFile ${APACHE_PID_FILE} Timeout 300 KeepAlive On MaxKeepAliveRequests 100 KeepAliveTimeout 5 ## ## Server-Pool Size Regulation (MPM specific) ## # prefork MPM # StartServers: number of server processes to start # MinSpareServers: minimum number of server processes which are kept spare # MaxSpareServers: maximum number of server processes which are kept spare # MaxClients: maximum number of server processes allowed to start # MaxRequestsPerChild: maximum number of requests a server process serves <IfModule mpm_prefork_module> StartServers 5 MinSpareServers 5 MaxSpareServers 10 MaxClients 150 MaxRequestsPerChild 0 </IfModule> # worker MPM # StartServers: initial number of server processes to start # MinSpareThreads: minimum number of worker threads which are kept spare # MaxSpareThreads: maximum number of worker threads which are kept spare # ThreadLimit: ThreadsPerChild can be changed to this maximum value during a # graceful restart. ThreadLimit can only be changed by stopping # and starting Apache. # ThreadsPerChild: constant number of worker threads in each server process # MaxClients: maximum number of simultaneous client connections # MaxRequestsPerChild: maximum number of requests a server process serves <IfModule mpm_worker_module> StartServers 2 MinSpareThreads 25 MaxSpareThreads 75 ThreadLimit 64 ThreadsPerChild 25 MaxClients 150 MaxRequestsPerChild 0 </IfModule> # event MPM # StartServers: initial number of server processes to start # MinSpareThreads: minimum number of worker threads which are kept spare # MaxSpareThreads: maximum number of worker threads which are kept spare # ThreadsPerChild: constant number of worker threads in each server process # MaxClients: maximum number of simultaneous client connections # MaxRequestsPerChild: maximum number of requests a server process serves <IfModule mpm_event_module> StartServers 2 MinSpareThreads 25 MaxSpareThreads 75 ThreadLimit 64 ThreadsPerChild 25 MaxClients 150 MaxRequestsPerChild 0 </IfModule> # These need to be set in /etc/apache2/envvars User ${APACHE_RUN_USER} Group ${APACHE_RUN_GROUP} # # AccessFileName: The name of the file to look for in each directory # for additional configuration directives. See also the AllowOverride # directive. # AccessFileName .htaccess # # The following lines prevent .htaccess and .htpasswd files from being # viewed by Web clients. # <Files ~ "^\.ht"> Order allow,deny Deny from all Satisfy all </Files> DefaultType None HostnameLookups Off ErrorLog ${APACHE_LOG_DIR}/error.log LogLevel debug # Include module configuration: Include mods-enabled/*.load Include mods-enabled/*.conf # Include list of ports to listen on and which to use for name based vhosts Include ports.conf # # The following directives define some format nicknames for use with # a CustomLog directive (see below). # If you are behind a reverse proxy, you might want to change %h into %{X-Forwarded-For}i # # LogFormat "%v:%p %h %l %u %t \"%r\" %>s %O \"%{Referer}i\" \"%{User-Agent}i\"" vhost_combined LogFormat "%h %l %u %t \"%r\" %>s %O \"%{Referer}i\" \"%{User-Agent}i\"" combined LogFormat "%h %l %u %t \"%r\" %>s %O" common LogFormat "%{Referer}i -> %U" referer LogFormat "%{User-agent}i" agent <Directory "/var/www"> Order allow,deny Allow from all Require all granted </Directory> # Include generic snippets of statements Include conf.d/ # Include the virtual host configurations: Include sites-enabled/*.conf NameVirtualHost *:80 /etc/apache2/sites-available/site1.net.conf <VirtualHost *:80> ServerName site1.net ServerAlias site1.net *.site1.net DocumentRoot "/var/www/site1" ErrorLog "/var/www/site1/logs/error.log" CustomLog "/var/www/site1/logs/access.log" vhost_combined <Directory "/var/www/site1"> Options None AllowOverride All Order allow,deny Allow from all Satisfy Any </Directory> </VirtualHost> /etc/apache2/sites-available/site2.com.conf <VirtualHost *:80> ServerName site2.com ServerAlias site2.com *.site2.com DocumentRoot "/var/www/site2" ErrorLog "/var/www/site2/logs/error.log" CustomLog "/var/www/site2/logs/access.log" vhost_combined <Directory "/var/www/site2"> Options None AllowOverride All Order allow,deny Allow from all Satisfy Any </Directory> </VirtualHost> I've also tried setting NameVirtualHost like: Listen 80 NameVirtualHost 23.88.121.82:80 NameVirtualHost 127.0.0.1:80 and the VirtualHost Directives: <VirtualHost 23.88.121.82:80> ... </VirtualHost> for both sites, but that causes the first site to fail, as well. I'm wondering if I need to set up individual IPs for each site, possibly? I have 2 more IPv4 and 3 IPv6 addresses available, if that would make a difference. Also, in the grand scheme of things, I will need to enable SSL for the first site. I've been reading that I'll need to basically just mimic the directives for listening on port 80, only on port 443, and make sure mod_ssl is enabled? EDIT: I just ran apache2 -t to test the config files that way, and got the error: apache2: bad user name ${APACHE_RUN_USER}. However, apachectl configtest returns Syntax OK. There are no other mentions of errors with the mutex anywhere else, however. I was pretty sure if there was an error with the user apache was supposed to run under, the server wouldn't start at all... EDIT 2: Restarting apache fixed the bad user name error.

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  • Is there a Linux distro specific for running as a host OS for Virtualization?

    - by harmh
    Hi, as I understand running VMware or other virtualizations requires a "host os". Normally this is one of your main os-es, that you really use. What I would like is a mini-linux and virtualization software pre-wrapped into a specialized bootalble, installable mini-os. So the linux would not have a webserver, nor X, just the minimum to run as a host OS and of course optimized for that, like some partitioning tools and such.

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  • Rule of thumb in RAM estimate for static pages? [closed]

    - by IMB
    Possible Duplicate: How do you do Load Testing and Capacity Planning for Web Sites I've seen tutorials saying they can run decent websites on 64MB RAM (Debian/Lighttpd/PHP/MySQL) however it's not clearly defined how much hits/traffic a "decent" site gets. Is there a rule of thumb on how much RAM a web server needs? To keep things simple, let's say you're running a site with static content and it's averaging at 100,000 hits per hour (HTML + images combined, no MySQL). How much RAM is the minimum requirement for that?

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  • How to preserve file attributes when one copies files in Windows?

    - by netvope
    On Linux, we can simply do: cp -pr directory How to do that in Windows? Can it be done in Windows Explorer? Any GUI tool suggestions? It would be the best if I can keep the NTFS permissions and creation/modification/access time. At a minimum, I need to preserve the modification date for the files and the directories. Windows Explorer's copy does not preserve the modification date for directories.

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  • What are the Best Virtual Desktop Managers for Windows 7 excluding Dexpot? [closed]

    - by user233641
    My question is different to others as my list of important features is completely different and I believe unique. Necessary Features Are: Dual-monitor support 6 desktops minimum Different icons can be created on different desktops Reliable and does not delete or remove icons without input from me Ability to save profiles and reload them if necessary Ability to change the home desktop to a different one Reasonably easy to use Keyboard Support Good email support

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  • Decreasing cached memory and increasing Free memory in RAM

    - by Greenhorn
    Hi, Im using windows 2007 server 64 bit OS, I've uploaded the snap shot of my task manager when minimum processes running It shows Total memory 8190 mb *Cached memory 4315 mb* Free 3402 mb So effectively I get only 3402 mb of total RAM usage My question here is more than half is used for cached memory is there any means I can decrease this cached memory inturn I can increase my free memory. I need to do this because my Application requires at least 5GB RAM and it crashed when run in this system. Please give me a solution for this Thanks in advance

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  • How to preserve file attributes when one copies files in Windows?

    - by netvope
    On Linux, we can simply do: cp -pr directory How to do that in Windows? Can it be done in Windows Explorer? Any GUI tool suggestions? It would be the best if I can keep the NTFS permissions and creation/modification/access time. At a minimum, I need to preserve the modification date for the files and the directories. Windows Explorer's copy does not preserve the modification date for directories.

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  • Gentoo/mdadm: Remove 1 disk from RAID 0 array

    - by Tim
    The server has a 7-disk RAID 0 array, and sdf is starting to die. Is there a way to remove sdf while keeping the array intact? # df -h Filesystem Size Used Avail Use% Mounted on /dev/md1 14T 6.6T 7.0T 49% /var [...] # cat /proc/mdstat Personalities : [raid0] md1 : active raid0 sda4[0] sdf1[5] sdd1[3] sdb1[1] sde1[4] sdg1[6] sdc1[2] 14482788352 blocks 512k chunks Looking to keep downtime to a minimum.

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  • WPF Databinding- Not your fathers databinding Part 1-3

    - by Shervin Shakibi
    As Promised here is my advanced databinding presentation from South Florida Code camp and also Orlando Code camp. you can find the demo files here. http://ssccinc.com/wpfdatabinding.zip Here is a quick description of the first demos, there will be 2 other Blogposting in the next few days getting into more advance databinding topics.   Example00 Here we have 3 textboxes, The first textbox mySourceElement Second textbox has a binding to mySourceElement and Path= Text <Binding ElementName="mySourceElement" Path="Text"  />   Third textbox is also bound to the Text property but we use inline Binding <TextBlock Text="{Binding ElementName=mySourceElement,Path=Text }" Grid.Row="2" /> Here is the entire XAML     <Grid  >           <Grid.RowDefinitions >             <RowDefinition Height="*" />             <RowDefinition Height="*" />             <RowDefinition Height="*" />         </Grid.RowDefinitions>         <TextBox Name="mySourceElement" Grid.Row="0"                  TextChanged="mySourceElement_TextChanged">Hello Orlnado</TextBox>         <TextBlock Grid.Row="1">                        <TextBlock.Text>                 <Binding ElementName="mySourceElement" Path="Text"  />             </TextBlock.Text>         </TextBlock>         <TextBlock Text="{Binding ElementName=mySourceElement,Path=Text }" Grid.Row="2" />     </Grid> </Window> Example01 we have a slider control, then we have two textboxes bound to the value property of the slider. one has its text property bound, the second has its fontsize property bound. <Grid>      <Grid.RowDefinitions >          <RowDefinition Height="40px" />          <RowDefinition Height="40px" />          <RowDefinition Height="*" />      </Grid.RowDefinitions>      <Slider Name="fontSizeSlider" Minimum="5" Maximum="100"              Value="10" Grid.Row="0" />      <TextBox Name="SizeTextBox"                    Text="{Binding ElementName=fontSizeSlider, Path=Value}" Grid.Row="1"/>      <TextBlock Text="Example 01"                 FontSize="{Binding ElementName=SizeTextBox,  Path=Text}"  Grid.Row="2"/> </Grid> Example02 very much like the previous example but it also has a font dropdown <Grid>      <Grid.RowDefinitions >          <RowDefinition Height="20px" />          <RowDefinition Height="40px" />          <RowDefinition Height="40px" />          <RowDefinition Height="*" />      </Grid.RowDefinitions>      <ComboBox Name="FontNameList" SelectedIndex="0" Grid.Row="0">          <ComboBoxItem Content="Arial" />          <ComboBoxItem Content="Calibri" />          <ComboBoxItem Content="Times New Roman" />          <ComboBoxItem Content="Verdana" />      </ComboBox>      <Slider Name="fontSizeSlider" Minimum="5" Maximum="100" Value="10" Grid.Row="1" />      <TextBox Name="SizeTextBox"      Text="{Binding ElementName=fontSizeSlider, Path=Value}" Grid.Row="2"/>      <TextBlock Text="Example 01" FontFamily="{Binding ElementName=FontNameList, Path=Text}"                 FontSize="{Binding ElementName=SizeTextBox,  Path=Text}"  Grid.Row="3"/> </Grid> Example03 In this example we bind to an object Employee.cs Notice we added a directive to our xaml which is clr-namespace and the namespace for our employee Class xmlns:local="clr-namespace:Example03" In Our windows Resources we create an instance of our object <Window.Resources>     <local:Employee x:Key="MyEmployee" EmployeeNumber="145"                     FirstName="John"                     LastName="Doe"                     Department="Product Development"                     Title="QA Manager" /> </Window.Resources> then we bind our container to the that instance of the data <Grid DataContext="{StaticResource MyEmployee}">         <Grid.RowDefinitions>             <RowDefinition Height="*" />             <RowDefinition Height="*" />             <RowDefinition Height="*" />             <RowDefinition Height="*" />             <RowDefinition Height="*" />         </Grid.RowDefinitions>         <Grid.ColumnDefinitions >             <ColumnDefinition Width="130px" />             <ColumnDefinition Width="178*" />         </Grid.ColumnDefinitions>     </Grid> and Finally we have textboxes that will bind to that textbox         <Label Grid.Row="0" Grid.Column="0">Employee Number</Label>         <TextBox Grid.Row="0" Grid.Column="1" Text="{Binding Path=EmployeeNumber}"></TextBox>         <Label Grid.Row="1" Grid.Column="0">First Name</Label>         <TextBox Grid.Row="1" Grid.Column="1" Text="{Binding Path=FirstName}"></TextBox>         <Label Grid.Row="2" Grid.Column="0">Last Name</Label>         <TextBox Grid.Row="2" Grid.Column="1" Text="{Binding Path=LastName}" />         <Label Grid.Row="3" Grid.Column="0">Title</Label>         <TextBox Grid.Row="3" Grid.Column="1" Text="{Binding Path=Title}"></TextBox>         <Label Grid.Row="4" Grid.Column="0">Department</Label>         <TextBox Grid.Row="4" Grid.Column="1" Text="{Binding Path=Department}" />

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  • A Taxonomy of Numerical Methods v1

    - by JoshReuben
    Numerical Analysis – When, What, (but not how) Once you understand the Math & know C++, Numerical Methods are basically blocks of iterative & conditional math code. I found the real trick was seeing the forest for the trees – knowing which method to use for which situation. Its pretty easy to get lost in the details – so I’ve tried to organize these methods in a way that I can quickly look this up. I’ve included links to detailed explanations and to C++ code examples. I’ve tried to classify Numerical methods in the following broad categories: Solving Systems of Linear Equations Solving Non-Linear Equations Iteratively Interpolation Curve Fitting Optimization Numerical Differentiation & Integration Solving ODEs Boundary Problems Solving EigenValue problems Enjoy – I did ! Solving Systems of Linear Equations Overview Solve sets of algebraic equations with x unknowns The set is commonly in matrix form Gauss-Jordan Elimination http://en.wikipedia.org/wiki/Gauss%E2%80%93Jordan_elimination C++: http://www.codekeep.net/snippets/623f1923-e03c-4636-8c92-c9dc7aa0d3c0.aspx Produces solution of the equations & the coefficient matrix Efficient, stable 2 steps: · Forward Elimination – matrix decomposition: reduce set to triangular form (0s below the diagonal) or row echelon form. If degenerate, then there is no solution · Backward Elimination –write the original matrix as the product of ints inverse matrix & its reduced row-echelon matrix à reduce set to row canonical form & use back-substitution to find the solution to the set Elementary ops for matrix decomposition: · Row multiplication · Row switching · Add multiples of rows to other rows Use pivoting to ensure rows are ordered for achieving triangular form LU Decomposition http://en.wikipedia.org/wiki/LU_decomposition C++: http://ganeshtiwaridotcomdotnp.blogspot.co.il/2009/12/c-c-code-lu-decomposition-for-solving.html Represent the matrix as a product of lower & upper triangular matrices A modified version of GJ Elimination Advantage – can easily apply forward & backward elimination to solve triangular matrices Techniques: · Doolittle Method – sets the L matrix diagonal to unity · Crout Method - sets the U matrix diagonal to unity Note: both the L & U matrices share the same unity diagonal & can be stored compactly in the same matrix Gauss-Seidel Iteration http://en.wikipedia.org/wiki/Gauss%E2%80%93Seidel_method C++: http://www.nr.com/forum/showthread.php?t=722 Transform the linear set of equations into a single equation & then use numerical integration (as integration formulas have Sums, it is implemented iteratively). an optimization of Gauss-Jacobi: 1.5 times faster, requires 0.25 iterations to achieve the same tolerance Solving Non-Linear Equations Iteratively find roots of polynomials – there may be 0, 1 or n solutions for an n order polynomial use iterative techniques Iterative methods · used when there are no known analytical techniques · Requires set functions to be continuous & differentiable · Requires an initial seed value – choice is critical to convergence à conduct multiple runs with different starting points & then select best result · Systematic - iterate until diminishing returns, tolerance or max iteration conditions are met · bracketing techniques will always yield convergent solutions, non-bracketing methods may fail to converge Incremental method if a nonlinear function has opposite signs at 2 ends of a small interval x1 & x2, then there is likely to be a solution in their interval – solutions are detected by evaluating a function over interval steps, for a change in sign, adjusting the step size dynamically. Limitations – can miss closely spaced solutions in large intervals, cannot detect degenerate (coinciding) solutions, limited to functions that cross the x-axis, gives false positives for singularities Fixed point method http://en.wikipedia.org/wiki/Fixed-point_iteration C++: http://books.google.co.il/books?id=weYj75E_t6MC&pg=PA79&lpg=PA79&dq=fixed+point+method++c%2B%2B&source=bl&ots=LQ-5P_taoC&sig=lENUUIYBK53tZtTwNfHLy5PEWDk&hl=en&sa=X&ei=wezDUPW1J5DptQaMsIHQCw&redir_esc=y#v=onepage&q=fixed%20point%20method%20%20c%2B%2B&f=false Algebraically rearrange a solution to isolate a variable then apply incremental method Bisection method http://en.wikipedia.org/wiki/Bisection_method C++: http://numericalcomputing.wordpress.com/category/algorithms/ Bracketed - Select an initial interval, keep bisecting it ad midpoint into sub-intervals and then apply incremental method on smaller & smaller intervals – zoom in Adv: unaffected by function gradient à reliable Disadv: slow convergence False Position Method http://en.wikipedia.org/wiki/False_position_method C++: http://www.dreamincode.net/forums/topic/126100-bisection-and-false-position-methods/ Bracketed - Select an initial interval , & use the relative value of function at interval end points to select next sub-intervals (estimate how far between the end points the solution might be & subdivide based on this) Newton-Raphson method http://en.wikipedia.org/wiki/Newton's_method C++: http://www-users.cselabs.umn.edu/classes/Summer-2012/csci1113/index.php?page=./newt3 Also known as Newton's method Convenient, efficient Not bracketed – only a single initial guess is required to start iteration – requires an analytical expression for the first derivative of the function as input. Evaluates the function & its derivative at each step. Can be extended to the Newton MutiRoot method for solving multiple roots Can be easily applied to an of n-coupled set of non-linear equations – conduct a Taylor Series expansion of a function, dropping terms of order n, rewrite as a Jacobian matrix of PDs & convert to simultaneous linear equations !!! Secant Method http://en.wikipedia.org/wiki/Secant_method C++: http://forum.vcoderz.com/showthread.php?p=205230 Unlike N-R, can estimate first derivative from an initial interval (does not require root to be bracketed) instead of inputting it Since derivative is approximated, may converge slower. Is fast in practice as it does not have to evaluate the derivative at each step. Similar implementation to False Positive method Birge-Vieta Method http://mat.iitm.ac.in/home/sryedida/public_html/caimna/transcendental/polynomial%20methods/bv%20method.html C++: http://books.google.co.il/books?id=cL1boM2uyQwC&pg=SA3-PA51&lpg=SA3-PA51&dq=Birge-Vieta+Method+c%2B%2B&source=bl&ots=QZmnDTK3rC&sig=BPNcHHbpR_DKVoZXrLi4nVXD-gg&hl=en&sa=X&ei=R-_DUK2iNIjzsgbE5ID4Dg&redir_esc=y#v=onepage&q=Birge-Vieta%20Method%20c%2B%2B&f=false combines Horner's method of polynomial evaluation (transforming into lesser degree polynomials that are more computationally efficient to process) with Newton-Raphson to provide a computational speed-up Interpolation Overview Construct new data points for as close as possible fit within range of a discrete set of known points (that were obtained via sampling, experimentation) Use Taylor Series Expansion of a function f(x) around a specific value for x Linear Interpolation http://en.wikipedia.org/wiki/Linear_interpolation C++: http://www.hamaluik.com/?p=289 Straight line between 2 points à concatenate interpolants between each pair of data points Bilinear Interpolation http://en.wikipedia.org/wiki/Bilinear_interpolation C++: http://supercomputingblog.com/graphics/coding-bilinear-interpolation/2/ Extension of the linear function for interpolating functions of 2 variables – perform linear interpolation first in 1 direction, then in another. Used in image processing – e.g. texture mapping filter. Uses 4 vertices to interpolate a value within a unit cell. Lagrange Interpolation http://en.wikipedia.org/wiki/Lagrange_polynomial C++: http://www.codecogs.com/code/maths/approximation/interpolation/lagrange.php For polynomials Requires recomputation for all terms for each distinct x value – can only be applied for small number of nodes Numerically unstable Barycentric Interpolation http://epubs.siam.org/doi/pdf/10.1137/S0036144502417715 C++: http://www.gamedev.net/topic/621445-barycentric-coordinates-c-code-check/ Rearrange the terms in the equation of the Legrange interpolation by defining weight functions that are independent of the interpolated value of x Newton Divided Difference Interpolation http://en.wikipedia.org/wiki/Newton_polynomial C++: http://jee-appy.blogspot.co.il/2011/12/newton-divided-difference-interpolation.html Hermite Divided Differences: Interpolation polynomial approximation for a given set of data points in the NR form - divided differences are used to approximately calculate the various differences. For a given set of 3 data points , fit a quadratic interpolant through the data Bracketed functions allow Newton divided differences to be calculated recursively Difference table Cubic Spline Interpolation http://en.wikipedia.org/wiki/Spline_interpolation C++: https://www.marcusbannerman.co.uk/index.php/home/latestarticles/42-articles/96-cubic-spline-class.html Spline is a piecewise polynomial Provides smoothness – for interpolations with significantly varying data Use weighted coefficients to bend the function to be smooth & its 1st & 2nd derivatives are continuous through the edge points in the interval Curve Fitting A generalization of interpolating whereby given data points may contain noise à the curve does not necessarily pass through all the points Least Squares Fit http://en.wikipedia.org/wiki/Least_squares C++: http://www.ccas.ru/mmes/educat/lab04k/02/least-squares.c Residual – difference between observed value & expected value Model function is often chosen as a linear combination of the specified functions Determines: A) The model instance in which the sum of squared residuals has the least value B) param values for which model best fits data Straight Line Fit Linear correlation between independent variable and dependent variable Linear Regression http://en.wikipedia.org/wiki/Linear_regression C++: http://www.oocities.org/david_swaim/cpp/linregc.htm Special case of statistically exact extrapolation Leverage least squares Given a basis function, the sum of the residuals is determined and the corresponding gradient equation is expressed as a set of normal linear equations in matrix form that can be solved (e.g. using LU Decomposition) Can be weighted - Drop the assumption that all errors have the same significance –-> confidence of accuracy is different for each data point. Fit the function closer to points with higher weights Polynomial Fit - use a polynomial basis function Moving Average http://en.wikipedia.org/wiki/Moving_average C++: http://www.codeproject.com/Articles/17860/A-Simple-Moving-Average-Algorithm Used for smoothing (cancel fluctuations to highlight longer-term trends & cycles), time series data analysis, signal processing filters Replace each data point with average of neighbors. Can be simple (SMA), weighted (WMA), exponential (EMA). Lags behind latest data points – extra weight can be given to more recent data points. Weights can decrease arithmetically or exponentially according to distance from point. Parameters: smoothing factor, period, weight basis Optimization Overview Given function with multiple variables, find Min (or max by minimizing –f(x)) Iterative approach Efficient, but not necessarily reliable Conditions: noisy data, constraints, non-linear models Detection via sign of first derivative - Derivative of saddle points will be 0 Local minima Bisection method Similar method for finding a root for a non-linear equation Start with an interval that contains a minimum Golden Search method http://en.wikipedia.org/wiki/Golden_section_search C++: http://www.codecogs.com/code/maths/optimization/golden.php Bisect intervals according to golden ratio 0.618.. Achieves reduction by evaluating a single function instead of 2 Newton-Raphson Method Brent method http://en.wikipedia.org/wiki/Brent's_method C++: http://people.sc.fsu.edu/~jburkardt/cpp_src/brent/brent.cpp Based on quadratic or parabolic interpolation – if the function is smooth & parabolic near to the minimum, then a parabola fitted through any 3 points should approximate the minima – fails when the 3 points are collinear , in which case the denominator is 0 Simplex Method http://en.wikipedia.org/wiki/Simplex_algorithm C++: http://www.codeguru.com/cpp/article.php/c17505/Simplex-Optimization-Algorithm-and-Implemetation-in-C-Programming.htm Find the global minima of any multi-variable function Direct search – no derivatives required At each step it maintains a non-degenerative simplex – a convex hull of n+1 vertices. Obtains the minimum for a function with n variables by evaluating the function at n-1 points, iteratively replacing the point of worst result with the point of best result, shrinking the multidimensional simplex around the best point. Point replacement involves expanding & contracting the simplex near the worst value point to determine a better replacement point Oscillation can be avoided by choosing the 2nd worst result Restart if it gets stuck Parameters: contraction & expansion factors Simulated Annealing http://en.wikipedia.org/wiki/Simulated_annealing C++: http://code.google.com/p/cppsimulatedannealing/ Analogy to heating & cooling metal to strengthen its structure Stochastic method – apply random permutation search for global minima - Avoid entrapment in local minima via hill climbing Heating schedule - Annealing schedule params: temperature, iterations at each temp, temperature delta Cooling schedule – can be linear, step-wise or exponential Differential Evolution http://en.wikipedia.org/wiki/Differential_evolution C++: http://www.amichel.com/de/doc/html/ More advanced stochastic methods analogous to biological processes: Genetic algorithms, evolution strategies Parallel direct search method against multiple discrete or continuous variables Initial population of variable vectors chosen randomly – if weighted difference vector of 2 vectors yields a lower objective function value then it replaces the comparison vector Many params: #parents, #variables, step size, crossover constant etc Convergence is slow – many more function evaluations than simulated annealing Numerical Differentiation Overview 2 approaches to finite difference methods: · A) approximate function via polynomial interpolation then differentiate · B) Taylor series approximation – additionally provides error estimate Finite Difference methods http://en.wikipedia.org/wiki/Finite_difference_method C++: http://www.wpi.edu/Pubs/ETD/Available/etd-051807-164436/unrestricted/EAMPADU.pdf Find differences between high order derivative values - Approximate differential equations by finite differences at evenly spaced data points Based on forward & backward Taylor series expansion of f(x) about x plus or minus multiples of delta h. Forward / backward difference - the sums of the series contains even derivatives and the difference of the series contains odd derivatives – coupled equations that can be solved. Provide an approximation of the derivative within a O(h^2) accuracy There is also central difference & extended central difference which has a O(h^4) accuracy Richardson Extrapolation http://en.wikipedia.org/wiki/Richardson_extrapolation C++: http://mathscoding.blogspot.co.il/2012/02/introduction-richardson-extrapolation.html A sequence acceleration method applied to finite differences Fast convergence, high accuracy O(h^4) Derivatives via Interpolation Cannot apply Finite Difference method to discrete data points at uneven intervals – so need to approximate the derivative of f(x) using the derivative of the interpolant via 3 point Lagrange Interpolation Note: the higher the order of the derivative, the lower the approximation precision Numerical Integration Estimate finite & infinite integrals of functions More accurate procedure than numerical differentiation Use when it is not possible to obtain an integral of a function analytically or when the function is not given, only the data points are Newton Cotes Methods http://en.wikipedia.org/wiki/Newton%E2%80%93Cotes_formulas C++: http://www.siafoo.net/snippet/324 For equally spaced data points Computationally easy – based on local interpolation of n rectangular strip areas that is piecewise fitted to a polynomial to get the sum total area Evaluate the integrand at n+1 evenly spaced points – approximate definite integral by Sum Weights are derived from Lagrange Basis polynomials Leverage Trapezoidal Rule for default 2nd formulas, Simpson 1/3 Rule for substituting 3 point formulas, Simpson 3/8 Rule for 4 point formulas. For 4 point formulas use Bodes Rule. Higher orders obtain more accurate results Trapezoidal Rule uses simple area, Simpsons Rule replaces the integrand f(x) with a quadratic polynomial p(x) that uses the same values as f(x) for its end points, but adds a midpoint Romberg Integration http://en.wikipedia.org/wiki/Romberg's_method C++: http://code.google.com/p/romberg-integration/downloads/detail?name=romberg.cpp&can=2&q= Combines trapezoidal rule with Richardson Extrapolation Evaluates the integrand at equally spaced points The integrand must have continuous derivatives Each R(n,m) extrapolation uses a higher order integrand polynomial replacement rule (zeroth starts with trapezoidal) à a lower triangular matrix set of equation coefficients where the bottom right term has the most accurate approximation. The process continues until the difference between 2 successive diagonal terms becomes sufficiently small. Gaussian Quadrature http://en.wikipedia.org/wiki/Gaussian_quadrature C++: http://www.alglib.net/integration/gaussianquadratures.php Data points are chosen to yield best possible accuracy – requires fewer evaluations Ability to handle singularities, functions that are difficult to evaluate The integrand can include a weighting function determined by a set of orthogonal polynomials. Points & weights are selected so that the integrand yields the exact integral if f(x) is a polynomial of degree <= 2n+1 Techniques (basically different weighting functions): · Gauss-Legendre Integration w(x)=1 · Gauss-Laguerre Integration w(x)=e^-x · Gauss-Hermite Integration w(x)=e^-x^2 · Gauss-Chebyshev Integration w(x)= 1 / Sqrt(1-x^2) Solving ODEs Use when high order differential equations cannot be solved analytically Evaluated under boundary conditions RK for systems – a high order differential equation can always be transformed into a coupled first order system of equations Euler method http://en.wikipedia.org/wiki/Euler_method C++: http://rosettacode.org/wiki/Euler_method First order Runge–Kutta method. Simple recursive method – given an initial value, calculate derivative deltas. Unstable & not very accurate (O(h) error) – not used in practice A first-order method - the local error (truncation error per step) is proportional to the square of the step size, and the global error (error at a given time) is proportional to the step size In evolving solution between data points xn & xn+1, only evaluates derivatives at beginning of interval xn à asymmetric at boundaries Higher order Runge Kutta http://en.wikipedia.org/wiki/Runge%E2%80%93Kutta_methods C++: http://www.dreamincode.net/code/snippet1441.htm 2nd & 4th order RK - Introduces parameterized midpoints for more symmetric solutions à accuracy at higher computational cost Adaptive RK – RK-Fehlberg – estimate the truncation at each integration step & automatically adjust the step size to keep error within prescribed limits. At each step 2 approximations are compared – if in disagreement to a specific accuracy, the step size is reduced Boundary Value Problems Where solution of differential equations are located at 2 different values of the independent variable x à more difficult, because cannot just start at point of initial value – there may not be enough starting conditions available at the end points to produce a unique solution An n-order equation will require n boundary conditions – need to determine the missing n-1 conditions which cause the given conditions at the other boundary to be satisfied Shooting Method http://en.wikipedia.org/wiki/Shooting_method C++: http://ganeshtiwaridotcomdotnp.blogspot.co.il/2009/12/c-c-code-shooting-method-for-solving.html Iteratively guess the missing values for one end & integrate, then inspect the discrepancy with the boundary values of the other end to adjust the estimate Given the starting boundary values u1 & u2 which contain the root u, solve u given the false position method (solving the differential equation as an initial value problem via 4th order RK), then use u to solve the differential equations. Finite Difference Method For linear & non-linear systems Higher order derivatives require more computational steps – some combinations for boundary conditions may not work though Improve the accuracy by increasing the number of mesh points Solving EigenValue Problems An eigenvalue can substitute a matrix when doing matrix multiplication à convert matrix multiplication into a polynomial EigenValue For a given set of equations in matrix form, determine what are the solution eigenvalue & eigenvectors Similar Matrices - have same eigenvalues. Use orthogonal similarity transforms to reduce a matrix to diagonal form from which eigenvalue(s) & eigenvectors can be computed iteratively Jacobi method http://en.wikipedia.org/wiki/Jacobi_method C++: http://people.sc.fsu.edu/~jburkardt/classes/acs2_2008/openmp/jacobi/jacobi.html Robust but Computationally intense – use for small matrices < 10x10 Power Iteration http://en.wikipedia.org/wiki/Power_iteration For any given real symmetric matrix, generate the largest single eigenvalue & its eigenvectors Simplest method – does not compute matrix decomposition à suitable for large, sparse matrices Inverse Iteration Variation of power iteration method – generates the smallest eigenvalue from the inverse matrix Rayleigh Method http://en.wikipedia.org/wiki/Rayleigh's_method_of_dimensional_analysis Variation of power iteration method Rayleigh Quotient Method Variation of inverse iteration method Matrix Tri-diagonalization Method Use householder algorithm to reduce an NxN symmetric matrix to a tridiagonal real symmetric matrix vua N-2 orthogonal transforms     Whats Next Outside of Numerical Methods there are lots of different types of algorithms that I’ve learned over the decades: Data Mining – (I covered this briefly in a previous post: http://geekswithblogs.net/JoshReuben/archive/2007/12/31/ssas-dm-algorithms.aspx ) Search & Sort Routing Problem Solving Logical Theorem Proving Planning Probabilistic Reasoning Machine Learning Solvers (eg MIP) Bioinformatics (Sequence Alignment, Protein Folding) Quant Finance (I read Wilmott’s books – interesting) Sooner or later, I’ll cover the above topics as well.

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  • Updating the managed debugging API for .NET v4

    - by Brian Donahue
    In any successful investigation, the right tools play a big part in collecting evidence about the state of the "crime scene" as it was before the detectives arrived. Unfortunately for the Crash Scene Investigator, we don't have the budget to fly out to the customer's site, chalk the outline, and eat their doughnuts. We have to rely on the end-user to collect the evidence for us, which means giving them the fingerprint dust and the evidence baggies and leaving them to it. With that in mind, the Red Gate support team have been writing tools that can collect vital clues with a minimum of fuss. Years ago we would have asked for a memory dump, where we used to get the customer to run CDB.exe and produce dumps that we could analyze in-house, but those dumps were pretty unwieldy (500MB files) and the debugger often didn't dump exactly where we wanted, or made five or more dumps. What we wanted was just the minimum state information from the program at the time of failure, so we produced a managed debugger that captured every first and second-chance exception and logged the stack and a minimal amount of variables from the memory of the application, which could all be exported as XML. This caused less inconvenience to the end-user because it is much easier to send a 65KB XML file in an email than a 500MB file containing all of the application's memory. We don't need to have the entire victim shipped out to us when we just want to know what was under the fingernails. The thing that made creating a managed debugging tool possible was the MDbg Engine example written by Microsoft as part of the Debugging Tools for Windows distribution. Since the ICorDebug interface is a bit difficult to understand, they had kindly created some wrappers that provided an event-driven debugging model that was perfect for our needs, but .NET 4 applications under debugging started complaining that "The debugger's protocol is incompatible with the debuggee". The introduction of .NET Framework v4 had changed the managed debugging API significantly, however, without an update for the MDbg Engine code! After a few hours of research, I had finally worked out that most of the version 4 ICorDebug interface still works much the same way in "legacy" v2 mode and there was a relatively easy fix for the problem in that you can still get a reference to legacy ICorDebug by changing the way the interface is created. In .NET v2, the interface was acquired using the CreateDebuggingInterfaceFromVersion method in mscoree.dll. In v4, you must first create IClrMetaHost, enumerate the runtimes, get an ICLRRuntimeInfo interface to the .NET 4 runtime from that, and use the GetInterface method in mscoree.dll to return a "legacy" ICorDebug interface. The rest of the MDbg Engine will continue working the old way. Here is how I had changed the MDbg Engine code to support .NET v4: private void InitFromVersion(string debuggerVersion){if( debuggerVersion.StartsWith("v1") ){throw new ArgumentException( "Can't debug a version 1 CLR process (\"" + debuggerVersion + "\"). Run application in a version 2 CLR, or use a version 1 debugger instead." );} ICorDebug rawDebuggingAPI=null;if (debuggerVersion.StartsWith("v4")){Guid CLSID_MetaHost = new Guid("9280188D-0E8E-4867-B30C-7FA83884E8DE"); Guid IID_MetaHost = new Guid("D332DB9E-B9B3-4125-8207-A14884F53216"); ICLRMetaHost metahost = (ICLRMetaHost)NativeMethods.ClrCreateInterface(CLSID_MetaHost, IID_MetaHost); IEnumUnknown runtimes = metahost.EnumerateInstalledRuntimes(); ICLRRuntimeInfo runtime = GetRuntime(runtimes, debuggerVersion); //Defined in metahost.hGuid CLSID_CLRDebuggingLegacy = new Guid(0xDF8395B5, 0xA4BA, 0x450b, 0xA7, 0x7C, 0xA9, 0xA4, 0x77, 0x62, 0xC5, 0x20);Guid IID_ICorDebug = new Guid("3D6F5F61-7538-11D3-8D5B-00104B35E7EF"); Object res;runtime.GetInterface(ref CLSID_CLRDebuggingLegacy, ref IID_ICorDebug, out res); rawDebuggingAPI = (ICorDebug)res; }elserawDebuggingAPI = NativeMethods.CreateDebuggingInterfaceFromVersion((int)CorDebuggerVersion.Whidbey,debuggerVersion);if (rawDebuggingAPI != null)InitFromICorDebug(rawDebuggingAPI);elsethrow new ArgumentException("Support for debugging version " + debuggerVersion + " is not yet implemented");} The changes above will ensure that the debugger can support .NET Framework v2 and v4 applications with the same codebase, but we do compile two different applications: one targeting v2 and the other v4. As a footnote I need to add that some missing native methods and wrappers, along with the EnumerateRuntimes method code, came from the Mindbg project on Codeplex. Another change is that when using the MDbgEngine.CreateProcess to launch a process in the debugger, do not supply a null as the final argument. This does not work any more because GetCORVersion always returns "v2.0.50727" as the function has been deprecated in .NET v4. What's worse is that on a system with only .NET 4, the user will be prompted to download and install .NET v2! Not nice! This works much better: proc = m_Debugger.CreateProcess(ProcessName, ProcessArgs, DebugModeFlag.Default,String.Format("v{0}.{1}.{2}",System.Environment.Version.Major,System.Environment.Version.Minor,System.Environment.Version.Build)); Microsoft "unofficially" plan on updating the MDbg samples soon, but if you have an MDbg-based application, you can get it working right now by changing one method a bit and adding a few new interfaces (ICLRMetaHost, IEnumUnknown, and ICLRRuntimeInfo). The new, non-legacy implementation of MDbg Engine will add new, interesting features like dump-file support and by association I assume garbage-collection/managed object stats, so it will be well worth looking into if you want to extend the functionality of a managed debugger going forward.

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  • Samba folder is gone

    - by bioShark
    I seem to have some issues sharing folders from my Ubuntu 12.04 machine to a Win7 machine. After playing around with the settings, I decided to revert to Samba's original setting by reinstalling it: sudo apt-get purge samba sudo rm -rf /etc/samba/ /etc/default/samba sudo apt-get install samba just to be sure I also run: sudo apt-get install samba samba-common system-config-samba winbind Now, I can't find /etc/samba folder any more. Even when I try to share a folder through Nautilus, I get: Samba's testparm returned error 1: Load smb config files from /etc/samba/smb.conf rlimit_max: increasing rlimit_max (1024) to minimum Windows limit (16384) params.c:OpenConfFile() - Unable to open configuration file "/etc/samba/smb.conf": No such file or directory Error loading services. Same when I try to list: xxx@xxx:~$ ll /etc/samba ls: cannot access /etc/samba: No such file or directory Any ideas what I did wrong, or what other package am I missing? cheers

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  • help with fixing fwts errors log

    - by jasmines
    Here is an extract of results.log: MTRR validation. Test 1 of 3: Validate the kernel MTRR IOMEM setup. FAILED [MEDIUM] MTRRIncorrectAttr: Test 1, Memory range 0xc0000000 to 0xdfffffff (PCI Bus 0000:00) has incorrect attribute Write-Combining. FAILED [MEDIUM] MTRRIncorrectAttr: Test 1, Memory range 0xfee01000 to 0xffffffff (PCI Bus 0000:00) has incorrect attribute Write-Protect. ==================================================================================================== Test 1 of 1: Kernel log error check. Kernel message: [ 0.208079] [Firmware Bug]: ACPI: BIOS _OSI(Linux) query ignored ADVICE: This is not exactly a failure mode but a warning from the kernel. The _OSI() method has implemented a match to the 'Linux' query in the DSDT and this is redundant because the ACPI driver matches onto the Windows _OSI strings by default. FAILED [HIGH] KlogACPIErrorMethodExecutionParse: Test 1, HIGH Kernel message: [ 3.512783] ACPI Error : Method parse/execution failed [\_SB_.PCI0.GFX0._DOD] (Node f7425858), AE_AML_PACKAGE_LIMIT (20110623/psparse-536) ADVICE: This is a bug picked up by the kernel, but as yet, the firmware test suite has no diagnostic advice for this particular problem. Found 1 unique errors in kernel log. ==================================================================================================== Check if system is using latest microcode. ---------------------------------------------------------------------------------------------------- Cannot read microcode file /usr/share/misc/intel-microcode.dat. Aborted test, initialisation failed. ==================================================================================================== MSR register tests. FAILED [MEDIUM] MSRCPUsInconsistent: Test 1, MSR SYSENTER_ESP (0x175) has 1 inconsistent values across 2 CPUs for (shift: 0 mask: 0xffffffffffffffff). MSR CPU 0 -> 0xf7bb9c40 vs CPU 1 -> 0xf7bc7c40 FAILED [MEDIUM] MSRCPUsInconsistent: Test 1, MSR MISC_ENABLE (0x1a0) has 1 inconsistent values across 2 CPUs for (shift: 0 mask: 0x400c51889). MSR CPU 0 -> 0x850088 vs CPU 1 -> 0x850089 ==================================================================================================== Checks firmware has set PCI Express MaxReadReq to a higher value on non-motherboard devices. ---------------------------------------------------------------------------------------------------- Test 1 of 1: Check firmware settings MaxReadReq for PCI Express devices. MaxReadReq for pci://00:00:1b.0 Audio device: Intel Corporation 82801I (ICH9 Family) HD Audio Controller (rev 03) is low (128) [Audio device]. MaxReadReq for pci://00:02:00.0 Network controller: Intel Corporation PRO/Wireless 5100 AGN [Shiloh] Network Connection is low (128) [Network controller]. FAILED [LOW] LowMaxReadReq: Test 1, 2 devices have low MaxReadReq settings. Firmware may have configured these too low. ADVICE: The MaxReadRequest size is set too low and will affect performance. It will provide excellent bus sharing at the cost of bus data transfer rates. Although not a critical issue, it may be worth considering setting the MaxReadRequest size to 256 or 512 to increase throughput on the PCI Express bus. Some drivers (for example the Brocade Fibre Channel driver) allow one to override the firmware settings. Where possible, this BIOS configuration setting is worth increasing it a little more for better performance at a small reduction of bus sharing. ==================================================================================================== PCIe ASPM check. ---------------------------------------------------------------------------------------------------- Test 1 of 2: PCIe ASPM ACPI test. PCIE ASPM is not controlled by Linux kernel. ADVICE: BIOS reports that Linux kernel should not modify ASPM settings that BIOS configured. It can be intentional because hardware vendors identified some capability bugs between the motherboard and the add-on cards. Test 2 of 2: PCIe ASPM registers test. WARNING: Test 2, RP 00h:1Ch.01h L0s not enabled. WARNING: Test 2, RP 00h:1Ch.01h L1 not enabled. WARNING: Test 2, Device 02h:00h.00h L0s not enabled. WARNING: Test 2, Device 02h:00h.00h L1 not enabled. PASSED: Test 2, PCIE aspm setting matched was matched. WARNING: Test 2, RP 00h:1Ch.05h L0s not enabled. WARNING: Test 2, RP 00h:1Ch.05h L1 not enabled. WARNING: Test 2, Device 85h:00h.00h L0s not enabled. WARNING: Test 2, Device 85h:00h.00h L1 not enabled. PASSED: Test 2, PCIE aspm setting matched was matched. ==================================================================================================== Extract and analyse Windows Management Instrumentation (WMI). Test 1 of 2: Check Windows Management Instrumentation in DSDT Found WMI Method WMAA with GUID: 5FB7F034-2C63-45E9-BE91-3D44E2C707E4, Instance 0x01 Found WMI Event, Notifier ID: 0x80, GUID: 95F24279-4D7B-4334-9387-ACCDC67EF61C, Instance 0x01 PASSED: Test 1, GUID 95F24279-4D7B-4334-9387-ACCDC67EF61C is handled by driver hp-wmi (Vendor: HP). Found WMI Event, Notifier ID: 0xa0, GUID: 2B814318-4BE8-4707-9D84-A190A859B5D0, Instance 0x01 FAILED [MEDIUM] WMIUnknownGUID: Test 1, GUID 2B814318-4BE8-4707-9D84-A190A859B5D0 is unknown to the kernel, a driver may need to be implemented for this GUID. ADVICE: A WMI driver probably needs to be written for this event. It can checked for using: wmi_has_guid("2B814318-4BE8-4707-9D84-A190A859B5D0"). One can install a notify handler using wmi_install_notify_handler("2B814318-4BE8-4707-9D84-A190A859B5D0", handler, NULL). http://lwn.net/Articles/391230 describes how to write an appropriate driver. Found WMI Object, Object ID AB, GUID: 05901221-D566-11D1-B2F0-00A0C9062910, Instance 0x01, Flags: 00 Found WMI Method WMBA with GUID: 1F4C91EB-DC5C-460B-951D-C7CB9B4B8D5E, Instance 0x01 Found WMI Object, Object ID BC, GUID: 2D114B49-2DFB-4130-B8FE-4A3C09E75133, Instance 0x7f, Flags: 00 Found WMI Object, Object ID BD, GUID: 988D08E3-68F4-4C35-AF3E-6A1B8106F83C, Instance 0x19, Flags: 00 Found WMI Object, Object ID BE, GUID: 14EA9746-CE1F-4098-A0E0-7045CB4DA745, Instance 0x01, Flags: 00 Found WMI Object, Object ID BF, GUID: 322F2028-0F84-4901-988E-015176049E2D, Instance 0x01, Flags: 00 Found WMI Object, Object ID BG, GUID: 8232DE3D-663D-4327-A8F4-E293ADB9BF05, Instance 0x01, Flags: 00 Found WMI Object, Object ID BH, GUID: 8F1F6436-9F42-42C8-BADC-0E9424F20C9A, Instance 0x00, Flags: 00 Found WMI Object, Object ID BI, GUID: 8F1F6435-9F42-42C8-BADC-0E9424F20C9A, Instance 0x00, Flags: 00 Found WMI Method WMAC with GUID: 7391A661-223A-47DB-A77A-7BE84C60822D, Instance 0x01 Found WMI Object, Object ID BJ, GUID: DF4E63B6-3BBC-4858-9737-C74F82F821F3, Instance 0x05, Flags: 00 ==================================================================================================== Disassemble DSDT to check for _OSI("Linux"). ---------------------------------------------------------------------------------------------------- Test 1 of 1: Disassemble DSDT to check for _OSI("Linux"). This is not strictly a failure mode, it just alerts one that this has been defined in the DSDT and probably should be avoided since the Linux ACPI driver matches onto the Windows _OSI strings { If (_OSI ("Linux")) { Store (0x03E8, OSYS) } If (_OSI ("Windows 2001")) { Store (0x07D1, OSYS) } If (_OSI ("Windows 2001 SP1")) { Store (0x07D1, OSYS) } If (_OSI ("Windows 2001 SP2")) { Store (0x07D2, OSYS) } If (_OSI ("Windows 2006")) { Store (0x07D6, OSYS) } If (LAnd (MPEN, LEqual (OSYS, 0x07D1))) { TRAP (0x01, 0x48) } TRAP (0x03, 0x35) } WARNING: Test 1, DSDT implements a deprecated _OSI("Linux") test. ==================================================================================================== 0 passed, 0 failed, 1 warnings, 0 aborted, 0 skipped, 0 info only. ==================================================================================================== ACPI DSDT Method Semantic Tests. ACPICA Exception AE_AML_INFINITE_LOOP during execution of method COMP Failed to install global event handler. Test 22 of 93: Check _PSR (Power Source). ACPICA Exception AE_AML_INFINITE_LOOP during execution of method COMP WARNING: Test 22, Detected an infinite loop when evaluating method '\_SB_.AC__._PSR'. ADVICE: This may occur because we are emulating the execution in this test environment and cannot handshake with the embedded controller or jump to the BIOS via SMIs. However, the fact that AML code spins forever means that lockup conditions are not being checked for in the AML bytecode. PASSED: Test 22, \_SB_.AC__._PSR correctly acquired and released locks 16 times. Test 35 of 93: Check _TMP (Thermal Zone Current Temp). ACPICA Exception AE_AML_INFINITE_LOOP during execution of method COMP WARNING: Test 35, Detected an infinite loop when evaluating method '\_TZ_.DTSZ._TMP'. ADVICE: This may occur because we are emulating the execution in this test environment and cannot handshake with the embedded controller or jump to the BIOS via SMIs. However, the fact that AML code spins forever means that lockup conditions are not being checked for in the AML bytecode. PASSED: Test 35, \_TZ_.DTSZ._TMP correctly acquired and released locks 14 times. ACPICA Exception AE_AML_INFINITE_LOOP during execution of method COMP WARNING: Test 35, Detected an infinite loop when evaluating method '\_TZ_.CPUZ._TMP'. ADVICE: This may occur because we are emulating the execution in this test environment and cannot handshake with the embedded controller or jump to the BIOS via SMIs. However, the fact that AML code spins forever means that lockup conditions are not being checked for in the AML bytecode. PASSED: Test 35, \_TZ_.CPUZ._TMP correctly acquired and released locks 10 times. ACPICA Exception AE_AML_INFINITE_LOOP during execution of method COMP WARNING: Test 35, Detected an infinite loop when evaluating method '\_TZ_.SKNZ._TMP'. ADVICE: This may occur because we are emulating the execution in this test environment and cannot handshake with the embedded controller or jump to the BIOS via SMIs. However, the fact that AML code spins forever means that lockup conditions are not being checked for in the AML bytecode. PASSED: Test 35, \_TZ_.SKNZ._TMP correctly acquired and released locks 10 times. PASSED: Test 35, _TMP correctly returned sane looking value 0x00000b4c (289.2 degrees K) PASSED: Test 35, \_TZ_.BATZ._TMP correctly acquired and released locks 9 times. PASSED: Test 35, _TMP correctly returned sane looking value 0x00000aac (273.2 degrees K) PASSED: Test 35, \_TZ_.FDTZ._TMP correctly acquired and released locks 7 times. Test 46 of 93: Check _DIS (Disable). FAILED [MEDIUM] MethodShouldReturnNothing: Test 46, \_SB_.PCI0.LPCB.SIO_.COM1._DIS returned values, but was expected to return nothing. Object returned: INTEGER: 0x00000000 ADVICE: This probably won't cause any errors, but it should be fixed as the AML code is not conforming to the expected behaviour as described in the ACPI specification. FAILED [MEDIUM] MethodShouldReturnNothing: Test 46, \_SB_.PCI0.LPCB.SIO_.LPT0._DIS returned values, but was expected to return nothing. Object returned: INTEGER: 0x00000000 ADVICE: This probably won't cause any errors, but it should be fixed as the AML code is not conforming to the expected behaviour as described in the ACPI specification. Test 61 of 93: Check _WAK (System Wake). Test _WAK(1) System Wake, State S1. ACPICA Exception AE_AML_INFINITE_LOOP during execution of method COMP WARNING: Test 61, Detected an infinite loop when evaluating method '\_WAK'. ADVICE: This may occur because we are emulating the execution in this test environment and cannot handshake with the embedded controller or jump to the BIOS via SMIs. However, the fact that AML code spins forever means that lockup conditions are not being checked for in the AML bytecode. Test _WAK(2) System Wake, State S2. ACPICA Exception AE_AML_INFINITE_LOOP during execution of method COMP WARNING: Test 61, Detected an infinite loop when evaluating method '\_WAK'. ADVICE: This may occur because we are emulating the execution in this test environment and cannot handshake with the embedded controller or jump to the BIOS via SMIs. However, the fact that AML code spins forever means that lockup conditions are not being checked for in the AML bytecode. Test _WAK(3) System Wake, State S3. ACPICA Exception AE_AML_INFINITE_LOOP during execution of method COMP WARNING: Test 61, Detected an infinite loop when evaluating method '\_WAK'. ADVICE: This may occur because we are emulating the execution in this test environment and cannot handshake with the embedded controller or jump to the BIOS via SMIs. However, the fact that AML code spins forever means that lockup conditions are not being checked for in the AML bytecode. Test _WAK(4) System Wake, State S4. ACPICA Exception AE_AML_INFINITE_LOOP during execution of method COMP WARNING: Test 61, Detected an infinite loop when evaluating method '\_WAK'. ADVICE: This may occur because we are emulating the execution in this test environment and cannot handshake with the embedded controller or jump to the BIOS via SMIs. However, the fact that AML code spins forever means that lockup conditions are not being checked for in the AML bytecode. Test _WAK(5) System Wake, State S5. ACPICA Exception AE_AML_INFINITE_LOOP during execution of method COMP WARNING: Test 61, Detected an infinite loop when evaluating method '\_WAK'. ADVICE: This may occur because we are emulating the execution in this test environment and cannot handshake with the embedded controller or jump to the BIOS via SMIs. However, the fact that AML code spins forever means that lockup conditions are not being checked for in the AML bytecode. Test 87 of 93: Check _BCL (Query List of Brightness Control Levels Supported). Package has 2 elements: 00: INTEGER: 0x00000000 01: INTEGER: 0x00000000 FAILED [MEDIUM] Method_BCLElementCount: Test 87, Method _BCL should return a package of more than 2 integers, got just 2. Test 88 of 93: Check _BCM (Set Brightness Level). ACPICA Exception AE_AML_PACKAGE_LIMIT during execution of method _BCM FAILED [CRITICAL] AEAMLPackgeLimit: Test 88, Detected error 'Package limit' when evaluating '\_SB_.PCI0.GFX0.DD02._BCM'. ==================================================================================================== ACPI table settings sanity checks. ---------------------------------------------------------------------------------------------------- Test 1 of 1: Check ACPI tables. PASSED: Test 1, Table APIC passed. Table ECDT not present to check. FAILED [MEDIUM] FADT32And64BothDefined: Test 1, FADT 32 bit FIRMWARE_CONTROL is non-zero, and X_FIRMWARE_CONTROL is also non-zero. Section 5.2.9 of the ACPI specification states that if the FIRMWARE_CONTROL is non-zero then X_FIRMWARE_CONTROL must be set to zero. ADVICE: The FADT FIRMWARE_CTRL is a 32 bit pointer that points to the physical memory address of the Firmware ACPI Control Structure (FACS). There is also an extended 64 bit version of this, the X_FIRMWARE_CTRL pointer that also can point to the FACS. Section 5.2.9 of the ACPI specification states that if the X_FIRMWARE_CTRL field contains a non zero value then the FIRMWARE_CTRL field *must* be zero. This error is also detected by the Linux kernel. If FIRMWARE_CTRL and X_FIRMWARE_CTRL are defined, then the kernel just uses the 64 bit version of the pointer. PASSED: Test 1, Table HPET passed. PASSED: Test 1, Table MCFG passed. PASSED: Test 1, Table RSDT passed. PASSED: Test 1, Table RSDP passed. Table SBST not present to check. PASSED: Test 1, Table XSDT passed. ==================================================================================================== Re-assemble DSDT and find syntax errors and warnings. ---------------------------------------------------------------------------------------------------- Test 1 of 2: Disassemble and reassemble DSDT FAILED [HIGH] AMLAssemblerError4043: Test 1, Assembler error in line 2261 Line | AML source ---------------------------------------------------------------------------------------------------- 02258| 0x00000000, // Range Minimum 02259| 0xFEDFFFFF, // Range Maximum 02260| 0x00000000, // Translation Offset 02261| 0x00000000, // Length | ^ | error 4043: Invalid combination of Length and Min/Max fixed flags 02262| ,, _Y0E, AddressRangeMemory, TypeStatic) 02263| DWordMemory (ResourceProducer, PosDecode, MinFixed, MaxFixed, Cacheable, ReadWrite, 02264| 0x00000000, // Granularity ==================================================================================================== ADVICE: (for error #4043): This occurs if the length is zero and just one of the resource MIF/MAF flags are set, or the length is non-zero and resource MIF/MAF flags are both set. These are illegal combinations and need to be fixed. See section 6.4.3.5 Address Space Resource Descriptors of version 4.0a of the ACPI specification for more details. FAILED [HIGH] AMLAssemblerError4050: Test 1, Assembler error in line 2268 Line | AML source ---------------------------------------------------------------------------------------------------- 02265| 0xFEE01000, // Range Minimum 02266| 0xFFFFFFFF, // Range Maximum 02267| 0x00000000, // Translation Offset 02268| 0x011FEFFF, // Length | ^ | error 4050: Length is not equal to fixed Min/Max window 02269| ,, , AddressRangeMemory, TypeStatic) 02270| }) 02271| Method (_CRS, 0, Serialized) ==================================================================================================== ADVICE: (for error #4050): The minimum address is greater than the maximum address. This is illegal. FAILED [HIGH] AMLAssemblerError1104: Test 1, Assembler error in line 8885 Line | AML source ---------------------------------------------------------------------------------------------------- 08882| Method (_DIS, 0, NotSerialized) 08883| { 08884| DSOD (0x02) 08885| Return (0x00) | ^ | warning level 0 1104: Reserved method should not return a value (_DIS) 08886| } 08887| 08888| Method (_SRS, 1, NotSerialized) ==================================================================================================== FAILED [HIGH] AMLAssemblerError1104: Test 1, Assembler error in line 9195 Line | AML source ---------------------------------------------------------------------------------------------------- 09192| Method (_DIS, 0, NotSerialized) 09193| { 09194| DSOD (0x01) 09195| Return (0x00) | ^ | warning level 0 1104: Reserved method should not return a value (_DIS) 09196| } 09197| 09198| Method (_SRS, 1, NotSerialized) ==================================================================================================== FAILED [HIGH] AMLAssemblerError1127: Test 1, Assembler error in line 9242 Line | AML source ---------------------------------------------------------------------------------------------------- 09239| CreateWordField (CRES, \_SB.PCI0.LPCB.SIO.LPT0._CRS._Y21._MAX, MAX2) 09240| CreateByteField (CRES, \_SB.PCI0.LPCB.SIO.LPT0._CRS._Y21._LEN, LEN2) 09241| CreateWordField (CRES, \_SB.PCI0.LPCB.SIO.LPT0._CRS._Y22._INT, IRQ0) 09242| CreateWordField (CRES, \_SB.PCI0.LPCB.SIO.LPT0._CRS._Y23._DMA, DMA0) | ^ | warning level 0 1127: ResourceTag smaller than Field (Tag: 8 bits, Field: 16 bits) 09243| If (RLPD) 09244| { 09245| Store (0x00, Local0) ==================================================================================================== FAILED [HIGH] AMLAssemblerError1128: Test 1, Assembler error in line 18682 Line | AML source ---------------------------------------------------------------------------------------------------- 18679| Store (0x01, Index (DerefOf (Index (Local0, 0x02)), 0x01)) 18680| If (And (WDPE, 0x40)) 18681| { 18682| Wait (\_SB.BEVT, 0x10) | ^ | warning level 0 1128: Result is not used, possible operator timeout will be missed 18683| } 18684| 18685| Store (BRID, Index (DerefOf (Index (Local0, 0x02)), 0x02)) ==================================================================================================== ADVICE: (for warning level 0 #1128): The operation can possibly timeout, and hence the return value indicates an timeout error. However, because the return value is not checked this very probably indicates that the code is buggy. A possible scenario is that a mutex times out and the code attempts to access data in a critical region when it should not. This will lead to undefined behaviour. This should be fixed. Table DSDT (0) reassembly: Found 2 errors, 4 warnings. Test 2 of 2: Disassemble and reassemble SSDT PASSED: Test 2, SSDT (0) reassembly, Found 0 errors, 0 warnings. FAILED [HIGH] AMLAssemblerError1104: Test 2, Assembler error in line 60 Line | AML source ---------------------------------------------------------------------------------------------------- 00057| { 00058| Store (CPDC (Arg0), Local0) 00059| GCAP (Local0) 00060| Return (Local0) | ^ | warning level 0 1104: Reserved method should not return a value (_PDC) 00061| } 00062| 00063| Method (_OSC, 4, NotSerialized) ==================================================================================================== FAILED [HIGH] AMLAssemblerError1104: Test 2, Assembler error in line 174 Line | AML source ---------------------------------------------------------------------------------------------------- 00171| { 00172| Store (\_PR.CPU0.CPDC (Arg0), Local0) 00173| GCAP (Local0) 00174| Return (Local0) | ^ | warning level 0 1104: Reserved method should not return a value (_PDC) 00175| } 00176| 00177| Method (_OSC, 4, NotSerialized) ==================================================================================================== FAILED [HIGH] AMLAssemblerError1104: Test 2, Assembler error in line 244 Line | AML source ---------------------------------------------------------------------------------------------------- 00241| { 00242| Store (\_PR.CPU0.CPDC (Arg0), Local0) 00243| GCAP (Local0) 00244| Return (Local0) | ^ | warning level 0 1104: Reserved method should not return a value (_PDC) 00245| } 00246| 00247| Method (_OSC, 4, NotSerialized) ==================================================================================================== FAILED [HIGH] AMLAssemblerError1104: Test 2, Assembler error in line 290 Line | AML source ---------------------------------------------------------------------------------------------------- 00287| { 00288| Store (\_PR.CPU0.CPDC (Arg0), Local0) 00289| GCAP (Local0) 00290| Return (Local0) | ^ | warning level 0 1104: Reserved method should not return a value (_PDC) 00291| } 00292| 00293| Method (_OSC, 4, NotSerialized) ==================================================================================================== Table SSDT (1) reassembly: Found 0 errors, 4 warnings. PASSED: Test 2, SSDT (2) reassembly, Found 0 errors, 0 warnings. PASSED: Test 2, SSDT (3) reassembly, Found 0 errors, 0 warnings. ==================================================================================================== 3 passed, 10 failed, 0 warnings, 0 aborted, 0 skipped, 0 info only. ==================================================================================================== Critical failures: 1 method test, at 1 log line: 1449: Detected error 'Package limit' when evaluating '\_SB_.PCI0.GFX0.DD02._BCM'. High failures: 11 klog test, at 1 log line: 121: HIGH Kernel message: [ 3.512783] ACPI Error: Method parse/execution failed [\_SB_.PCI0.GFX0._DOD] (Node f7425858), AE_AML_PACKAGE_LIMIT (20110623/psparse-536) syntaxcheck test, at 1 log line: 1668: Assembler error in line 2261 syntaxcheck test, at 1 log line: 1687: Assembler error in line 2268 syntaxcheck test, at 1 log line: 1703: Assembler error in line 8885 syntaxcheck test, at 1 log line: 1716: Assembler error in line 9195 syntaxcheck test, at 1 log line: 1729: Assembler error in line 9242 syntaxcheck test, at 1 log line: 1742: Assembler error in line 18682 syntaxcheck test, at 1 log line: 1766: Assembler error in line 60 syntaxcheck test, at 1 log line: 1779: Assembler error in line 174 syntaxcheck test, at 1 log line: 1792: Assembler error in line 244 syntaxcheck test, at 1 log line: 1805: Assembler error in line 290 Medium failures: 9 mtrr test, at 1 log line: 76: Memory range 0xc0000000 to 0xdfffffff (PCI Bus 0000:00) has incorrect attribute Write-Combining. mtrr test, at 1 log line: 78: Memory range 0xfee01000 to 0xffffffff (PCI Bus 0000:00) has incorrect attribute Write-Protect. msr test, at 1 log line: 165: MSR SYSENTER_ESP (0x175) has 1 inconsistent values across 2 CPUs for (shift: 0 mask: 0xffffffffffffffff). msr test, at 1 log line: 173: MSR MISC_ENABLE (0x1a0) has 1 inconsistent values across 2 CPUs for (shift: 0 mask: 0x400c51889). wmi test, at 1 log line: 528: GUID 2B814318-4BE8-4707-9D84-A190A859B5D0 is unknown to the kernel, a driver may need to be implemented for this GUID. method test, at 1 log line: 1002: \_SB_.PCI0.LPCB.SIO_.COM1._DIS returned values, but was expected to return nothing. method test, at 1 log line: 1011: \_SB_.PCI0.LPCB.SIO_.LPT0._DIS returned values, but was expected to return nothing. method test, at 1 log line: 1443: Method _BCL should return a package of more than 2 integers, got just 2. acpitables test, at 1 log line: 1643: FADT 32 bit FIRMWARE_CONTROL is non-zero, and X_FIRMWARE_CONTROL is also non-zero. 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