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  • Glibc importance of error ...

    - by Oz123
    Hi Everyone, I am following LFS 6.7, and I reached the point where I compile glibc-2.12.1 . I mounted the LFS partition with the atime option: here is a confirm on that I think: /dev/sdb1 on /mnt /lfs type ext4 (rw) I get the following errors on making the test, and I have no clue if I should try to resolve them, or just ignore them and go on ... rpc/types.h sunrpc/rpc/svc_auth.h sunrpc/rpcsvc/bootparam.h sysvipc/sys/ipc.h \ sysvipc/sys/msg.h sysvipc/sys/sem.h sysvipc/sys/shm.h termios/termios.h \ termios/sys/termios.h termios/sys/ttychars.h time/time.h time/sys/time.h \ time/sys/timeb.h wcsmbs/wchar.h wctype/wctype.h > \ /sources/glibc-build/begin-end-check.out make[1]: Target `check' not remade because of errors. make[1]: Leaving directory `/sources/glibc-2.12.1' make: *** [check] Error 2 root:/sources/glibc-build# grep Error glibc-check-log make[2]: *** [/sources/glibc-build/math/test-float.out] Error 1 make[2]: *** [/sources/glibc-build/math/test-ifloat.out] Error 1 make[1]: *** [math/tests] Error 2 make[2]: [/sources/glibc-build/posix/annexc.out] Error 1 (ignored) make: *** [check] Error 2 thanks in advance, Oz

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  • RDP from domain workstation to non-domain workstation via VPN

    - by SILENT
    I am trying to RDP from a domain computer to a non-domain computer over a VPN. I created a rdp profile for a specified user (for example user name: USERX) with the option to save the password. I am able to establish the connection the first time by entering in the password. However, from that point on, whenever the RDP link is reestablished, it would state that my login details were incorrect and ask me re-type the password for COMP\USERX. Problem is, I don't have a domain called COMP and the password would fail even if reentered. The only way I can reestablish the connection is by choosing the option to login as another user.

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  • When Your Boss Doesn't Want you to Succeed

    - by Phil Factor
    You're working hard to get an application finished. You are programming long into the evenings sometimes, and eating sandwiches at your desk instead of taking a lunch break. Then one day you glance up at the IT manager, serene in his mysterious round of meetings, and think 'Does he actually care whether this project succeeds or not?'. The question may seem absurd. Of course the project must succeed. The truth, as always, is often far more complex. Your manager may even be doing his best to make sure you don't succeed. Why? There have always been rich pickings for the unscrupulous in IT.  In extreme cases, where administrators struggle with scarcely-comprehended technical issues, huge sums of money can be lost and gained without any perceptible results. In a very few cases can fraud be proven: most of the time, the intricacies of the 'game' are such that one can do little more than harbor suspicion.  Where does over-enthusiastic salesmanship end and fraud begin? The Business of Information Technology provides rich opportunities for White-collar crime. The poor developer has his, or her, hands full with the task of wrestling with the sheer complexity of building an application. He, or she, has no time for following the complexities of the chicanery of the management that is directing affairs.  Most likely, the developers wouldn't even suspect that their company management had ulterior motives. I'll illustrate what I mean with an entirely fictional, hypothetical, example. The Opportunist and the Aged Charities often do good, unexciting work that is funded by the income from a bequest that dates back maybe hundreds of years.  In our example, it isn't exciting work, for it involves the welfare of elderly people who have fallen on hard times.  Volunteers visit, giving a smile and a chat, and check that they are all right, but are able to spend a little money on their discretion to ameliorate any pressing needs for these old folk.  The money is made to work very hard and the charity averts a great deal of suffering and eases the burden on the state. Daisy hears the garden gate creak as Mrs Rainer comes up the path. She looks forward to her twice-weekly visit from the nice lady from the trust. She always asked ‘is everything all right, Love’. Cheeky but nice. She likes her cheery manner. She seems interested in hearing her memories, and talking about her far-away family. She helps her with those chores in the house that she couldn’t manage and once even paid to fill the back-shed with coke, the other year. Nice, Mrs. Rainer is, she thought as she goes to open the door. The trustees are getting on in years themselves, and worry about the long-term future of the charity: is it relevant to modern society? Is it likely to attract a new generation of workers to take it on. They are instantly attracted by the arrival to the board of a smartly dressed University lecturer with the ear of the present Government. Alain 'Stalin' Jones is earnest, persuasive and energetic. The trustees welcome him to the board and quickly forgive his humorless political-correctness. He talks of 'diversity', 'relevance', 'social change', 'equality' and 'communities', but his eye is on that huge bequest. Alain first came to notice as a Trotskyite union official, who insinuated himself into one of the duller Trades Unions and turned it, through his passionate leadership, into a radical, headline-grabbing organization.  Middle age, and the rise of European federal socialism, had brought him quiet prosperity and charcoal suits, an ear in the current government, and a wide influence as a member of various Quangos (government bodies staffed by well-paid unelected courtiers).  He was employed as a 'consultant' by several organizations that relied on government contracts. After gaining the confidence of the trustees, and showing a surprising knowledge of mundane processes and the regulatory framework of charities, Alain launches his plan.  The trust will expand their work by means of a bold IT initiative that will coordinate the interventions of several 'caring agencies', and provide  emergency cover, a special Website so anxious relatives can see how their elderly charges are doing, and a vastly more efficient way of coordinating the work of the volunteer carers. It will also provide a special-purpose site that gives 'social networking' facilities, rather like Facebook, to the few elderly folk on the lists with access to the internet. The trustees perk up. Their own experience of the internet is restricted to the occasional scanning of railway timetables, but they can see that it is 'relevant'. In his next report to the other trustees, Alain proudly announces that all this glamorous and exciting technology can be paid for by a grant from the government. He admits darkly that he has influence. True to his word, the government promises a grant of a size that is an order of magnitude greater than any budget that the trustees had ever handled. There was the understandable proviso that the company that would actually do the IT work would have to be one of the government's preferred suppliers and the work would need to be tendered under EU competition rules. The only company that tenders, a multinational IT company with a long track record of government work, quotes ten million pounds for the work. A trustee questions the figure as it seems enormous for the reasonably trivial internet facilities being built, but the IT Salesmen dazzle them with presentations and three-letter acronyms until they subside into quiescent acceptance. After all, they can’t stay locked in the Twentieth century practices can they? The work is put in hand with a large project team, in a splendid glass building near west London. The trustees see rooms of programmers working diligently at screens, and who talk with enthusiasm of the project. Paul, the project manager, looked through his resource schedule with growing unease. His initial excitement at being given his first major project hadn’t lasted. He’d been allocated a lackluster team of developers whose skills didn’t seem right, and he was allowed only a couple of contractors to make good the deficit. Strangely, the presentation he’d given to his management, where he’d saved time and resources with a OTS solution to a great deal of the development work, and a sound conservative architecture, hadn’t gone down nearly as big as he’d hoped. He almost got the feeling they wanted a more radical and ambitious solution. The project starts slipping its dates. The costs build rapidly. There are certain uncomfortable extra charges that appear, such as the £600-a-day charge by the 'Business Manager' appointed to act as a point of liaison between the charity and the IT Company.  When he appeared, his face permanently split by a 'Mr Sincerity' smile, they'd thought he was provided at the cost of the IT Company. Derek, the DBA, didn’t have to go to the server room quite some much as he did: but It got him away from the poisonous despair of the development group. Wave after wave of events had conspired to delay the project.  Why the management had imposed hideous extra bureaucracy to cover ISO 9000 and 9001:2008 accreditation just as the project was struggling to get back on-schedule was  beyond belief.  Then  the Business manager was coming back with endless changes in scope, sorrowing saying that the Trustees were very insistent, though hopelessly out in touch with the reality of technical challenges. Suddenly, the costs mount to the point of consuming the government grant in its entirety. The project remains tantalizingly just out of reach. Alain Jones gives an emotional rallying speech at the trustees review meeting, urging them not to lose their nerve. Sadly, the trustees dip into the accumulated capital of the trust, the seed-corn of all their revenues, in order to save the IT project. A few months later it is all over. The IT project is never delivered, even though it had seemed so incredibly close.  With the trust's capital all gone, the activities it funded have to be terminated and the trust becomes just a shell. There aren't even the funds to mount a legal challenge against the IT company, even had the trust's solicitor advised such a foolish thing. Alain leaves as suddenly as he had arrived, only to pop up a few months later, bronzed and rested, at another charity. The IT workers who were permanent employees are dispersed to other projects, and the contractors leave to other contracts. Within months the entire project is but a vague memory. One or two developers remain  puzzled that their managers had been so obstructive when they should have welcomed progress toward completion of the project, but they put it down to incompetence and testosterone. Few suspected that they were actively preventing the project from getting finished. The relationships between the IT consultancy, and the government of the day are intricate, and made more complex by the Private Finance initiatives and political patronage.  The losers in this case were the taxpayers, and the beneficiaries of the trust, and, perhaps the soul of the original benefactor of the trust, whose bid to give his name some immortality had been scuppered by smooth-talking white-collar political apparatniks.  Even now, nobody is certain whether a crime was ever committed. The perfect heist, I guess. Where’s the victim? "I hear that Daisy’s cottage is up for sale. She’s had to go into a care home.  She didn’t want to at all, but then there is nobody to keep an eye on her since she had that minor stroke a while back.  A charity used to help out. The ‘social’ don’t have the funding, evidently for community care. Yes, her old cat was put down. There was a good clearout, and now the house is all scrubbed and cleared ready for sale. The skip was full of old photos and letters, memories. No room in her new ‘home’."

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  • Need to add request headers to every request in Apache

    - by 115748146017471869327
    I'm trying to add a header value to every request via Apache (ver 2.2). I've edited my VirtualHost to include the following vaiations: (I've tried both RequestHeader and Header, add and set in all of these cases) RequestHeader set X-test_url "Test" or <Directory /> RequestHeader set X-test_url "Test" </Directory> or <Location ~ "/*" > RequestHeader set X-test_url "Test" </Location> It's hard to explain how I've gotten to this point, but I have to get this done in Apache. Again I'm trying to add the header value to every request. Thanks.

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  • Set up iis7.5 to deny connections outside of LAN for certain folder

    - by Darkcat Studios
    Im setting up a combined website and extranet currently, they both read from the same database on the same server as the site is hosted on. The reason being that the website is fed from the data that the staff plug into the extranet interface. it also links in to AD for authorising access to the extranet. I have the extranet in a folder within the website folder. What I want to do is only allow the extranet to be accessed from computers within our LAN, but allow the main website to be freely accessible to internet users. I have it set up as a generic web server currently, so anyone can view anything (well up to the point where the user is asked to log into the extranet of course! I have read a lot on this but nothing I read applies to, or works in IIS7.5

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  • DIVIDE vs division operator in #dax

    - by Marco Russo (SQLBI)
    Alberto Ferrari wrote an interesting article about DIVIDE performance in DAX. This new function has been introduced in SQL Server Analysis Services 2012 SP1, so it is available also in Excel 2013 (which still doesn’t have other features/fixes introduced by following Cumulative Updates…). The idea that instead of writing: IF ( Sales[Quantity] <> 0, Sales[Amount] / Sales[Quantity], BLANK () ) you can write: DIVIDE ( Sales[Amount], Sales[Quantity] ) There is a third optional argument in DIVIDE that defines the result in case the denominator (second argument) is zero, and by default its value is BLANK, so I omitted the third argument in my example. Using DIVIDE is very important, especially when you use a measure in MDX (for example in an Excel PivotTable) because it raise the chance that the non empty evaluation for the result is evaluated in bulk mode instead of cell-by-cell. However, from a DAX point of view, you might find it’s better to use the standard division operator removing the IF statement. I suggest you to read Alberto’s article, because you will find that an expression applying a filter using FILTER is faster than using CALCULATE, which is against any rule of thumb you might have read until now! Again, this is not always true, and depends on many conditions – trying to simplify, we might say that for a simple calculation, the query plan generated by FILTER could be more efficient – but, as usual, it depends, and 90% of the times using FILTER instead of CALCULATE produces slower performance. Do not take anything for granted, and always check the query plan when performance are your first issue!

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  • A record for www

    - by Manjoor
    My present DNS configuration for my website's A record is as below Name Value --------------------------- example.com 67.45.xx.xx www.example.com 67.45.xx.xx In above configuration user can open website either by example.com or by www.example.com. One of my SEO team-member argues for single point access. According to him search engine’s crawler see 2 different name with same content. It is not good and we should configure domain in such a way that if user open example.com then browser automatically get redirected to www.example.com. Now I have 2 questions Does above argument is valid? If yes then what changes I need to do in my DNS?

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  • Using dnsmasq dns server on a laptop for a locally hosted tld

    - by kimausloos
    Hi, I'm running a working apache install with mod vhost_alias on a laptop. Everything works, but I have to manually add hosts in my /etc/hosts file. I'd like to install dnsmasq to point a tld to my local machine (this is not the problem, I know how to add a wildcard tld to dnsmasq), but how do I make it so that it will go look for other dns servers upstream? Remember I'm talking about a laptop, so I will be working on various wifi hotspots, with different default gateways, dns servers, etc. I've searched for quite some time but the only things I find are guides that require you to hardcode the upstream servers wich is a no-go for me. Any help is appreciated!

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  • mac osX file recovery

    - by Daniel
    I thought that all operating systems would merge folder content when being moved to the same location. Imagine my surprise when that didn't happen and I have hundreds, if not thousands of files that have gone missing and are nowhere to be found. Because they were not "deleted" they are not in the trash bin. I've tried to do some recovery using a program called stellarPheonix but after about a 24hour scan, it didn't recognize any of the raw files (.dng,.arw) as image files and so I couldn't see if they could be recovered. It also didn't show the directory structure, which would be handy. I tried a quick scan, but all it showed was files that were still on the HD, not sure what the point of that is. I've used recover 2000 on Win and it does a good job, does anyone know of anything that works quickly and reliably for this kind of file recovery. (I don't think I should have to do a sector-by=sector for this kind of file loss)

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  • Creating an email notification system based on polling database rows

    - by Ashish Sharma
    I have to design an email notification system based on the following requirements: The email notifications would be created based on polling rows in a Mysql 5.5 DB table when they are in a particular 'Completed' state. The email notification should be sent out in no more than 5 minutes from the time the row was created in the DB table (At the time of DB table row creation the state of the row might not be 'Completed'). Once 5 minutes for the DB table row expire in reaching the 'Completed' state, separate email notification need to be sent (basically telling the user that the original email notification would be delayed) and then sending the email notification as and when the row state reaches to being 'Completed'. The rest of the system requirements are : Adding relevant checks to monitor the whole system via MBeans interface. The system should be scalable so that if the rate of DB table rows creation increases so does the Email notification system be able to ramp up. So I request suggestions on following lines: What approach should I take in solving the problem described from a programming/Design pattern point of view? Suggestion for any third party plugin/software that can be used to solve the problem described? Points to take care regarding scalability and monitoring the health of the system? Java is the language of preference but I am open to using off the shelf components that can be interfaced with Java language or provide standard ports for communication. Currently I do have an in house grown system (written in Java) that is catering to the specified requirements, but it's now crumbling under increased load and now I want to give the problem a fresh look. thanks in advance Ashish

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  • DNS Help (CNAMEs and A Records)

    - by Aaron Francis
    I'm trying to set up my DNS properly so that I can have hosting through PHPFog and email services using MailGun. PHPFog has us redirect the naked domain to the www and then use a CNAME to point the www to PHPFog and mailgun provides the MX records to use. The problem I'm having is that I have no A record set up on Hover because when I do, the CNAME no longer works (?), or at least it seems that way because I am no longer seeing my site from PHPFog, I'm seeing a Hover landing page. I know all the records I need, I just can't seem to get them to play nicely together. I've been told Amazon's Route 53 should be able to solve my problem, but I haven't yet figured out how. I just need to have hosting at PHPFog and email services through MailGun. As you can probably tell, I have only a very limited understanding of DNS, so forgive me if this is a silly question.

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  • Online remount btrfs of root filesystem with different subvolume (snapshot) [migrated]

    - by goncalopp
    Let's say you have a btrfs root filesystem on an online system. You want to revert the filesystem to an earlier state, of which you have a snapshot: remount /dev/sdaX / -o remount,subvol=snapshots/Y For the record, I've done this in a test system, and it does not work. The command returns with no errors, but the subvolume mounted is the same. If this did work, what would be the consequences? My guess is that open file descriptors would still point to the old subvolume, thus possibly leading to "data loss" on the new subvolume, if one was not careful. Assuming one goes to the trouble of closing and reopening all open file descriptors, does this sound feasible? Or are there other types of problems?

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  • Friend of Red Gate

    - by Nick Harrison
    Friend of Red Gate I recently joined the friend of Red Gate program.   I am very honored to be included in this group.    This program is a big part of Red Gates community outreach.   If you are not familiar with Red Gate, I urge you to check them out.    They have some wonderful tools for the SQL Server community and the DotNet community.    They are also building up some tools for Exchange and Oracle. I was invited to join this program primarliy because of my work with Simple Talk and promoting one of their newest products, Reflector. Reflector is a wonderful tool.   I doubt that anyone who has ever used it would argue that point. Red Gate did a wonderful job taking over the support of Reflector.   I know many people had their doubts.    The initial release under Red Gate should set those fears to rest.   I was very impressed with how their developers interacted with their users during the preview phase! Red Gate is also a good partner for the community.    They activly support the community, sponsoring Code Camps, sponsoring User Groups, supporting the Forums, etc. And their tools are pretty amazing as well.

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  • Managing Personal Projects As Solo Developer - Getting out of depth and failing projects

    - by James Jeffery
    I need some advice on project management. I start a project, and often times it will a large project for a solo developer. Usually its a web project. I handle everything from the UI, to the JS, PHP, server management etc. Half way in I feel out of my depth. I lose where I am, so I spend a couple of days away from the project to avoid the stress and before you know it, it becomes another unfinished project. I try to use frameworks and code libraries to make my developments easier on myself. Sometimes I will complete a project so it "works" and then go back and handle errors, design the UI properly and stuff. But without fail I will always end up out of my depth. I've though about outsourcing tasks such as the UI, and the behaviour, and focusing just on the PHP - which I feel is my strong point. But then pride kicks in, and I don't feel at one with a project I haven't completed myself. Does this make sense? I am sure there are many others who have felt like this either at home, or at work, and I would love some advice on managing my projects better.

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  • Ubuntu can't find the correct max resolution with Samsung SyncMaster SA300

    - by fatmatto
    i decided to install ubuntu also on my desktop PC (Windows has been exorcised from my life) but i am having some problems i didn't have with previous hardware configurations. My display is a Samsung SyncMaster SA300, on windows vista the maximum resolution (1920x1080) worked well, but now, ubuntu (after installing fglrx drivers) tells me that the maximum resolution is 1600x1200 I googled a lot last night, and i found a lot of people solving this (on different displays though) with xrandr. I was not able to do it, because xrandr keep complaining "you goddamn maximum resolution is 1600x1600". What xranrd clean command say is: mattia@fatdesktop:~$ xrandr Screen 0: minimum 320 x 200, current 1600 x 1200, maximum 1600 x 1600 DFP1 disconnected (normal left inverted right x axis y axis) CRT1 disconnected (normal left inverted right x axis y axis) CRT2 connected 1600x1200+0+0 (normal left inverted right x axis y axis) 0mm x 0mm 1600x1200 60.0*+ 1400x1050 60.0 1280x1024 60.0 47.0 43.0 1440x900 59.9 1280x960 60.0 1280x800 60.0 1152x864 60.0 47.0 43.0 1280x768 59.9 56.0 1280x720 60.0 50.0 1024x768 60.0 43.5 800x600 60.3 56.2 47.0 720x576 50.0 720x480 60.0 640x480 60.0 TV disconnected (normal left inverted right x axis y axis) CV disconnected (normal left inverted right x axis y axis) Then according to other internet posts and forums: mattia@fatdesktop:~$ cvt 1920 1080 60 # 1920x1080 59.96 Hz (CVT 2.07M9) hsync: 67.16 kHz; pclk: 173.00 MHz Modeline "1920x1080_60.00" 173.00 1920 2048 2248 2576 1080 1083 1088 1120 -hsync +vsync So now i have to add that modeline mattia@fatdesktop:~$ xrandr --newmode "1920x1080_60.00" 173.00 1920 2048 2248 2576 1080 1083 1088 1120 -hsync +vsync mattia@fatdesktop:~$ xrandr --addmode CRT2 1920x1080_60.00 And here comes the pain: mattia@fatdesktop:~$ xrandr --output CRT2 --mode 1920x1080_60.00 xrandr: **screen cannot be larger than 1600x1600 (desired size 1920x1080)** See? screen cannot be larger than 1600x1600 (desired size 1920x1080) At this point, the 1920x1080 option appears inside the resolution choice menu (the graphical one). But last night, when i tried to select it, my screen went black, and i had to power off the pc. Any clues? am i on the wrong path?

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  • Slide-decks from recent Adelaide SQL Server UG meetings

    - by Rob Farley
    The UK has been well represented this summer at the Adelaide SQL Server User Group, with presentations from Chris Testa-O’Neill (isn’t that the right link? Maybe try this one) and Martin Cairney. The slides are available here and here. I thought I’d particularly mention Martin’s, and how it’s relevant to this month’s T-SQL Tuesday. Martin spoke about Policy-Based Management and the Enterprise Policy Management Framework – something which is remarkably under-used, and yet which can really impact your ability to look after environments. If you have policies set up, then you can easily test each of your SQL instances to see if they are still satisfying a set of policies as defined. Automation (the topic of this month’s T-SQL Tuesday) should mean that your life is made easier, thereby enabling to you to do more. It shouldn’t remove the human element, but should remove (most of) the human errors. People still need to manage the situation, and work out what needs to be done, etc. We haven’t reached a point where computers can replace people, but they are very good at replace the mundaneness and monotony of our jobs. They’ve made our lives more interesting (although many would rightly argue that they have also made our lives more complex) by letting us focus on the stuff that changes. Martin named his talk Put Your Feet Up, which nicely expresses the fact that managing systems shouldn’t be about running around checking things all the time. It must be about having systems in place which tell you when things aren’t going well. It’s never quite as simple as being able to actually put your feet up, but certainly no system should require constant attention. It’s definitely a policy we at LobsterPot adhere to, whether it’s an alert to let us know that an ETL package has run successfully, or a script that generates some code for a report. If things can be automated, it reduces the chance of error, reduces the repetitive nature of work, and in general, keeps both consultants and clients much happier.

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  • Introducing Oracle VM VirtualBox

    - by Fat Bloke
    I guess these things always take longer than expected and, while the dust is still not completely settled in all the ex-Sun geographies, it is high time we started looking at some of the great new assets in the Oracle VM portfolio. So let's start with one of the most exciting: Oracle VM VirtualBox. VirtualBox is cross-platform virtualization software, oftentimes called a hypervisor, and it runs on Windows, Linux, Solaris and the Mac. Which means that you download it, you install it on your existing platform, and start creating and running virtual machines alongside your existing applications. For example, on my Mac I can run Oracle Enterprise Linux and Windows 7 alongside my Mac apps like this...(Click to zoom)VirtualBox use has grown phenomenally to the point that at Sun it was the 3rd most popular download behind Java and MySQL. Its success can be attributed to the fact that it doesn't need dedicated hardware, it can be installed on either client or server classes of computers, is very easy to use and is free for personal use. And, as you might expect, VirtualBox has it's own vibrant community too, over at www.virtualbox.org There are hundreds of tutorials out there about how to use VirtualBox to create vm's and install different operating systems ranging from Windows 7 to ChromeOS, and if you don't want to install an operating system yourself, you can download pre-built virtual appliances from community sites such as VirtualBox Images or commercial companies selling subscriptions to whole application stacks, such as JumpBox . In no time you'll be creating and sharing your own vm's using the VirtualBox OVF export and import function. VirtualBox is deceptively powerful. Under the simple GUI lies a formidable engine capable of running heavyweight multi-CPU virtual workloads, exhibiting Enterprise capabilities including a built-in remote display server, an iSCSI initiator for connecting to shared storage, and the ability to teleport running vm's from one host to another. And for solution builders, you should be aware that VirtualBox has a scriptable command line interface and an SDK and rich web service APIs. To get a further feel for what VirtualBox is capable of, check out some of these short movies or simply go download it for yourself.- FB

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  • What's up with LDoms: Part 1 - Introduction & Basic Concepts

    - by Stefan Hinker
    LDoms - the correct name is Oracle VM Server for SPARC - have been around for quite a while now.  But to my surprise, I get more and more requests to explain how they work or to give advise on how to make good use of them.  This made me think that writing up a few articles discussing the different features would be a good idea.  Now - I don't intend to rewrite the LDoms Admin Guide or to copy and reformat the (hopefully) well known "Beginners Guide to LDoms" by Tony Shoumack from 2007.  Those documents are very recommendable - especially the Beginners Guide, although based on LDoms 1.0, is still a good place to begin with.  However, LDoms have come a long way since then, and I hope to contribute to their adoption by discussing how they work and what features there are today.  In this and the following posts, I will use the term "LDoms" as a common abbreviation for Oracle VM Server for SPARC, just because it's a lot shorter and easier to type (and presumably, read). So, just to get everyone on the same baseline, lets briefly discuss the basic concepts of virtualization with LDoms.  LDoms make use of a hypervisor as a layer of abstraction between real, physical hardware and virtual hardware.  This virtual hardware is then used to create a number of guest systems which each behave very similar to a system running on bare metal:  Each has its own OBP, each will install its own copy of the Solaris OS and each will see a certain amount of CPU, memory, disk and network resources available to it.  Unlike some other type 1 hypervisors running on x86 hardware, the SPARC hypervisor is embedded in the system firmware and makes use both of supporting functions in the sun4v SPARC instruction set as well as the overall CPU architecture to fulfill its function. The CMT architecture of the supporting CPUs (T1 through T4) provide a large number of cores and threads to the OS.  For example, the current T4 CPU has eight cores, each running 8 threads, for a total of 64 threads per socket.  To the OS, this looks like 64 CPUs.  The SPARC hypervisor, when creating guest systems, simply assigns a certain number of these threads exclusively to one guest, thus avoiding the overhead of having to schedule OS threads to CPUs, as do typical x86 hypervisors.  The hypervisor only assigns CPUs and then steps aside.  It is not involved in the actual work being dispatched from the OS to the CPU, all it does is maintain isolation between different guests. Likewise, memory is assigned exclusively to individual guests.  Here,  the hypervisor provides generic mappings between the physical hardware addresses and the guest's views on memory.  Again, the hypervisor is not involved in the actual memory access, it only maintains isolation between guests. During the inital setup of a system with LDoms, you start with one special domain, called the Control Domain.  Initially, this domain owns all the hardware available in the system, including all CPUs, all RAM and all IO resources.  If you'd be running the system un-virtualized, this would be what you'd be working with.  To allow for guests, you first resize this initial domain (also called a primary domain in LDoms speak), assigning it a small amount of CPU and memory.  This frees up most of the available CPU and memory resources for guest domains.  IO is a little more complex, but very straightforward.  When LDoms 1.0 first came out, the only way to provide IO to guest systems was to create virtual disk and network services and attach guests to these services.  In the meantime, several different ways to connect guest domains to IO have been developed, the most recent one being SR-IOV support for network devices released in version 2.2 of Oracle VM Server for SPARC. I will cover these more advanced features in detail later.  For now, lets have a short look at the initial way IO was virtualized in LDoms: For virtualized IO, you create two services, one "Virtual Disk Service" or vds, and one "Virtual Switch" or vswitch.  You can, of course, also create more of these, but that's more advanced than I want to cover in this introduction.  These IO services now connect real, physical IO resources like a disk LUN or a networt port to the virtual devices that are assigned to guest domains.  For disk IO, the normal case would be to connect a physical LUN (or some other storage option that I'll discuss later) to one specific guest.  That guest would be assigned a virtual disk, which would appear to be just like a real LUN to the guest, while the IO is actually routed through the virtual disk service down to the physical device.  For network, the vswitch acts very much like a real, physical ethernet switch - you connect one physical port to it for outside connectivity and define one or more connections per guest, just like you would plug cables between a real switch and a real system. For completeness, there is another service that provides console access to guest domains which mimics the behavior of serial terminal servers. The connections between the virtual devices on the guest's side and the virtual IO services in the primary domain are created by the hypervisor.  It uses so called "Logical Domain Channels" or LDCs to create point-to-point connections between all of these devices and services.  These LDCs work very similar to high speed serial connections and are configured automatically whenever the Control Domain adds or removes virtual IO. To see all this in action, now lets look at a first example.  I will start with a newly installed machine and configure the control domain so that it's ready to create guest systems. In a first step, after we've installed the software, let's start the virtual console service and downsize the primary domain.  root@sun # ldm list NAME STATE FLAGS CONS VCPU MEMORY UTIL UPTIME primary active -n-c-- UART 512 261632M 0.3% 2d 13h 58m root@sun # ldm add-vconscon port-range=5000-5100 \ primary-console primary root@sun # svcadm enable vntsd root@sun # svcs vntsd STATE STIME FMRI online 9:53:21 svc:/ldoms/vntsd:default root@sun # ldm set-vcpu 16 primary root@sun # ldm set-mau 1 primary root@sun # ldm start-reconf primary root@sun # ldm set-memory 7680m primary root@sun # ldm add-config initial root@sun # shutdown -y -g0 -i6 So what have I done: I've defined a range of ports (5000-5100) for the virtual network terminal service and then started that service.  The vnts will later provide console connections to guest systems, very much like serial NTS's do in the physical world. Next, I assigned 16 vCPUs (on this platform, a T3-4, that's two cores) to the primary domain, freeing the rest up for future guest systems.  I also assigned one MAU to this domain.  A MAU is a crypto unit in the T3 CPU.  These need to be explicitly assigned to domains, just like CPU or memory.  (This is no longer the case with T4 systems, where crypto is always available everywhere.) Before I reassigned the memory, I started what's called a "delayed reconfiguration" session.  That avoids actually doing the change right away, which would take a considerable amount of time in this case.  Instead, I'll need to reboot once I'm all done.  I've assigned 7680MB of RAM to the primary.  That's 8GB less the 512MB which the hypervisor uses for it's own private purposes.  You can, depending on your needs, work with less.  I'll spend a dedicated article on sizing, discussing the pros and cons in detail. Finally, just before the reboot, I saved my work on the ILOM, to make this configuration available after a powercycle of the box.  (It'll always be available after a simple reboot, but the ILOM needs to know the configuration of the hypervisor after a power-cycle, before the primary domain is booted.) Now, lets create a first disk service and a first virtual switch which is connected to the physical network device igb2. We will later use these to connect virtual disks and virtual network ports of our guest systems to real world storage and network. root@sun # ldm add-vds primary-vds root@sun # ldm add-vswitch net-dev=igb2 switch-primary primary You are free to choose whatever names you like for the virtual disk service and the virtual switch.  I strongly recommend that you choose names that make sense to you and describe the function of each service in the context of your implementation.  For the vswitch, for example, you could choose names like "admin-vswitch" or "production-network" etc. This already concludes the configuration of the control domain.  We've freed up considerable amounts of CPU and RAM for guest systems and created the necessary infrastructure - console, vts and vswitch - so that guests systems can actually interact with the outside world.  The system is now ready to create guests, which I'll describe in the next section. For further reading, here are some recommendable links: The LDoms 2.2 Admin Guide The "Beginners Guide to LDoms" The LDoms Information Center on MOS LDoms on OTN

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  • StackCenter 2 - Now in Public Beta!

    - by George Edison
    Visit now: http://stackcenter.quickmediasolutions.com/beta/ Feedback is appreciated! About StackCenter 2 has been brewing for quite some time now. Since the global inbox was introduced, the original StackCenter was rendered mostly useless and the need for a replacement was born. And now, I present StackCenter 2! Its goal is to be a dashboard for everything StackExchange such as rep. graphs, images, or whatever! Currently, there are 3 widgets and it is now possible to write your own - just follow the link on your dashboard's home page. After registering, simply click on the 'add widgets...' link to get started. Some things might not work quite right. (This is in beta after all.) Any feedback you can provide is welcome! License Closed source at this point. Platform StackCenter should run fine on any web browser that has JavaScript enabled. (StackCenter 2 uses a lot of JavaScript.) Contact Email: [email protected] Code PHP (using the CakePHP framework), JavaScript, and of course, HTML

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  • Bind9 as a caching resolver fails with mismatch ID on localhost but not external IP

    - by argibbs
    I'm running Ubuntu 12.04 LTS on a machine on my private network. I have bind9 installed (v9.8.1-P1) via aptitude, so it appears to have put all the bits in the right places and the service starts automatically. I plan on adding some zones later, but first I'm just trying to get it working as a caching resolver. I installed bind, configured it, and starting using it. Initially I thought it was working ok, but then I found some sites weren't being resolved. I've pinned it down to being linked to the size of the result and bind failing-over to TCP mode. So: I'm trying to find out why bind is failing when I query for domain info and the result is 512 bytes (causing a truncation and retry on TCP). Specifically it fails with ID mismatches if I point dig at localhost, but works when I query the machine's own IP (192.168.0.2). This appears to be backwards to the problem that most people have when using bind (fails on external ip, works on localhost). If I do dig @localhost google.com (which has a response of <512 bytes) then it works; I get no warnings, and plenty of output. $ dig @localhost google.com ; <<>> DiG 9.8.1-P1 <<>> @localhost google.com [snip lots of output] ;; Query time: 39 msec ;; SERVER: 127.0.0.1#53(127.0.0.1) ;; WHEN: Thu Oct 17 23:08:34 2013 ;; MSG SIZE rcvd: 495 If I do dig @localhost play.google.com (which has a larger response) then I get back something like: $ dig @localhost play.google.com ;; Truncated, retrying in TCP mode. ;; ERROR: ID mismatch: expected ID 3696, got 27130 This seems to be standard, documented behaviour - when the UDP response is large (here 'large' == 512 bytes) it falls back to TCP. The ID mismatch is not expected though. If I do dig @192.168.0.2 play.google.com then I still get the warning about using TCP mode, but it otherwise works $ dig @192.168.0.2 play.google.com ;; Truncated, retrying in TCP mode. ; <<>> DiG 9.8.1-P1 <<>> @192.168.0.2 play.google.com [snip most of the output] ;; Query time: 5 msec ;; SERVER: 192.168.0.2#53(192.168.0.2) ;; WHEN: Thu Oct 17 23:05:55 2013 ;; MSG SIZE rcvd: 521 At the moment I've not set up any zones in my local instance, so it's just acting as a caching resolver. My options config is pretty much unchanged from standard, I've got the following set: options { directory "/var/cache/bind"; allow-query { 192.168/16; 127.0.0.1; }; forwarders { 8.8.8.8; 8.8.4.4; }; dnssec-validation auto; edns-udp-size 4096 ; allow-transfer { any; }; auth-nxdomain no; # conform to RFC1035 listen-on-v6 { any; }; }; And my /etc/resolv.conf is just nameserver 127.0.0.1 search .local The problem definitely seems linked to the failover to TCP mode: if I do dig +bufsize=4096 @localhost play.google.com then it works; no warning about failover to TCP, no ID mismatch, and a standard looking result. To be honest, if there was a way to force bind to use a much larger UDP buffer, that'd probably be good enough for me, but all I've been able to find mention of is max-udp-size 4096 and that doesn't change the behaviour in any way. I've also tried setting edns-udp-size 512 in case the problem is some weird EDNS issue with my router (which seems unlikely since the +bufsize=4096 flag works fine). I've also tried dig +trace @localhost play.google.com; this works. No truncation/TCP warning, and a full result. I've also tried changing the servers used in the forwarder (e.g. to OpenDNS), but that makes no difference. There's one last data point: if I repetitively do dig @localhost play.google.com I don't always get an ID mismatch, but sometimes a REFUSED error. I'm much more likely to get a REFUSED error if I dig the non-localhost IP (192.168.0.2) first: $ dig @localhost play.google.com ;; Truncated, retrying in TCP mode. ; <<>> DiG 9.8.1-P1 <<>> @localhost play.google.com ; (1 server found) ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: REFUSED, id: 35104 ;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 0 ;; QUESTION SECTION: ;play.google.com. IN A ;; Query time: 4 msec ;; SERVER: 127.0.0.1#53(127.0.0.1) ;; WHEN: Thu Oct 17 23:20:13 2013 ;; MSG SIZE rcvd: 33 Any insights or things to try would be much appreciated.

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  • Replacement mouse "feet"?

    - by Jeff Atwood
    The plastic skid pad "feet" on the bottom of my Logitech G9 mouse (which I love!) are getting rather worn down -- to the point that the outer shell of the mouse scrapes on the mousepad a bit. I've had the mouse for about ~2 years now so it does get a lot (I mean lot of use). But, I hate to buy a new mouse when I only need replacement "feet". Where can I obtain replacement mouse feet? Is this even possible?

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  • How to know my wireless card has injection enabled?

    - by shrimpy
    I am playing around with aircrack. And was trying to see whether my wireless card on my laptop can pass the injection test And I end up seeing the following... does it mean my wireless card is not able to run aircrack? root@myubuntu:/home/myubuntu# iwconfig lo no wireless extensions. eth0 no wireless extensions. eth1 IEEE 802.11bg ESSID:"" Nickname:"" Mode:Managed Frequency:2.437 GHz Access Point: Not-Associated Bit Rate:54 Mb/s Tx-Power:24 dBm Retry min limit:7 RTS thr:off Fragment thr:off Power Management:off Link Quality=5/5 Signal level=0 dBm Noise level=-57 dBm Rx invalid nwid:0 Rx invalid crypt:781 Rx invalid frag:0 Tx excessive retries:0 Invalid misc:0 Missed beacon:0 root@myubuntu:/home/myubuntu# aireplay-ng -9 eth1 ioctl(SIOCSIWMODE) failed: Invalid argument ARP linktype is set to 1 (Ethernet) - expected ARPHRD_IEEE80211, ARPHRD_IEEE80211_FULL or ARPHRD_IEEE80211_PRISM instead. Make sure RFMON is enabled: run 'airmon-ng start eth1 <#>' Sysfs injection support was not found either. root@myubuntu:/home/myubuntu#

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  • Home networking - Wireless switch?

    - by gamers2000
    I currently have a Linksys WRT160N that has a couple wireless clients and a few wired clients. We are planning to switch from DSL to cable and unfortunately, there isn't a cable point in a location close to the wired clients (i.e. the new location of the router would be too far from the wired clients to lay Ethernet cables). Thus, I was wondering if there was a wireless switch of some sort in which it would be a standard Ethernet switch that would connect to my wireless network? (This is a home network,of course.)

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  • Picasa “sync to web” folders do not stay in sync

    - by jmbouffard
    I have multiple folders from the Picasa software that were moved to my Google+ profile using the "sync to web" feature. At some point I noticed that some of these folders were on Google+ and had the green upload arrow in Picasa, however the "sync to web" option was disabled. I tried to re-enable the "sync to web" option and it starts loading but after a few seconds the "sync to web" option is back to disabled. I get no error message, it just switches back to disable. Is there any way I could leave the option enabled? Out of around 80 something albums synced to Google+ only 3-4 are not able to have the "sync to web" option enabled. Thanks.

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  • SQL Server 2005 to 2008 upgrade - are MDF files binary compatible?

    - by james
    I have 50 databases on a MS SQL Server 2005 system and want to upgrade to MS SQL Server 2008. This is what I tried on some test machines: 1. copied the \DATA directory from the source (MSSQL 2005) to exactly the same path on the target (MSSQL 2008) server. 2. edited the startup parameters on the MSSQL 2008 service to point to the path of the MSSQL 2005 master database. 3. restarted MSSQL service It worked and I can access all databases, tables and data. My questions are: I go back to SQL Server 4.2 and it has never been this easy. I know it worked, but should have it worked? Am I missing something, or is there going to be a gotcha next week? These are simple databases, with just tables, views and indexes. No cross database links, no triggers etc

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