Search Results

Search found 3657 results on 147 pages for 'motion planning'.

Page 118/147 | < Previous Page | 114 115 116 117 118 119 120 121 122 123 124 125  | Next Page >

• Two DHCP servers on the same network

  - by CesarGon

  We are setting up a routing link between the Windows Server 2008 networks of two different buildings in my organisation. Each network uses a different IP addressing scheme (one uses public addresses, the other one uses private), but the goal is having a single Windows Server domain across the gap between the buildings. The link is provided by a 100-Mbps point-to-point line. I have always understood that you should not have more than one DHCP server on a network. However, we are planning to put a domain controller on each building, and each domain controller will be a DNS server and a DHCP server as well. The intention is that a machine booting up in building A gets its IP address from the DHCP server closer to it, in building A, while a machine booting up in building B gets an address from the DHCP server in building B. Since the two buildings will be linked and the network will be only one, will this work? How can I avoid that a machine booting up in building A gets an address from the DHCP server in building B (or vice versa)? Thanks.

  Read the article

• Two DHCP servers on the same network

  - by CesarGon

  We are setting up a routing link between the Windows Server 2008 networks of two different buildings in my organisation. Each network uses a different IP addressing scheme (one uses public addresses, the other one uses private), but the goal is having a single Windows Server domain across the gap between the buildings. The link is provided by a 100-Mbps point-to-point line. I have always understood that you should not have more than one DHCP server on a network. However, we are planning to put a domain controller on each building, and each domain controller will be a DNS server and a DHCP server as well. The intention is that a machine booting up in building A gets its IP address from the DHCP server closer to it, in building A, while a machine booting up in building B gets an address from the DHCP server in building B. Since the two buildings will be linked and the network will be only one, will this work? How can I avoid that a machine booting up in building A gets an address from the DHCP server in building B (or vice versa)? Thanks.

  Read the article

• httpd 2.2.15 + suPHP + suExec + php5 = permission and information ?

  - by Prix

  Hi, i am currently playing around with suexec, suphp, php5 on my apache on slackware 13.1. Everything is installed and working properly but now i did like to got further into the directory permissions and at suphp settings and options available. initially i was planning to leave suphp disabled unless a virtualhost has it specified to be enabled but it does not seem to work, see sample: mod_php.conf which is included in my httpd.conf # # mod_php & mod_suPHP - PHP Hypertext Preprocessor module # # Load the PHP module: LoadModule php5_module lib/httpd/modules/libphp5.so # Load the suPHP module: LoadModule suphp_module lib/httpd/modules/mod_suphp.so <IfModule mod_php5.c> # Tell Apache to feed all *.php files through PHP. If you'd like to # parse PHP embedded in files with different extensions, comment out # these lines and see the example below. <FilesMatch \.php$> SetHandler application/x-httpd-php </FilesMatch> </IfModule> <IfModule mod_suphp.c> # This option tells mod_suphp if a PHP-script requested on this server (or # VirtualHost) should be run with the PHP-interpreter or returned to the # browser "as it is". suPHP_Engine off </IfModule> With the above first sample it makes suPHP and PHP not work if i comment out the php5 stuff but the module it will run just fine ... So my first question is, how could i possible make this setup work ? Leave suPHP disabled using php5 by default and if a virtualhost has suPHP enabled it will disable php5 and use suPHP. if any information is lacked here please let me know and i will update with any additional information you may need. Thanks in advance.

  Read the article

• Virtual Fileserver

  - by Sergei

  Hi, We are planning to move our production servers to the datacenter and virtualize remaining servers in the process.Datacenter will have HP blades with vSphere on top.Currentliy we are using Celerra NS20 as fileserver.Since datacenter is using HP kit and EVA 4400 as SAN, we cannot have Celerra there, as EMC supoprt for Celerra does not work for non EMC array. I have searched for possible options and one of them was to have HP NAS blade X3800sb instead of Celerra.However this seems like overkill for me.We are only using Celerra for about 100 users and 50 servers and I think having X3800sb could be waste of resources. The other option would be to have a virtual fileserver as a part of vmware environment in datacenter.We only need CIFS to be provided.The only option I can think of is Windows Storage server.We had a bad expirience with Windows servers used as fileservers ( memory leaks one thing) in the past and this was one of the reasons we moved to Celerra. What are the other options?We need something as reliable as Celerra with as many options as possible.For example , Celerra has per folder quotas, deduplication, dynamic volume allocation, automatic failover, VTLU, replication. Also we would need to replicate NAS data to the failover site.We could use block level replication , SAN-to-SAN, but this would mean wasted bandwidth, as we need only subset of folders to be replicated.We used CA XSoft for windows servers in the past and Celerra has option for Celerra replication. Thank you very much in advance, Please ask me if I missed any details!

  Read the article

• Experiences in Upgrading from Exchange 2003 to Exchange 2010

  - by gWaldo

  I'm currently running Exchange 2003 SP2 Cluster on a Server 2003 AD Forest (in native 2003 mode), and we beginning to plan the upgrade to Server 2008 AD and Exchange 2010. We have two main sites, one middle-sized office, and a couple of smaller sites which have DCs (which may be RODCs after the upgrade). Currently all of our Exchange cluster is in my main site, but we are considering using the new datastore paradigm for load-balance/failover at the other large site, but this is not set in stone. Right now we are in the information-gathering and planning phases. I am looking for input of any gotchas experienced while performing either upgrade, but especially the Exchange upgrade. Gotchas? What surprised you? What wasn't documented? What said one thing but was misleading? (Confusing either in content or severity.) What is great or horrible about the new system? What worked well? What worked poorly? If you were to do it over again...? (I know that this isn't so much a question that can be definitively answered, but I'm happy to reward insight and useful resources (not the Microsoft documentation, but Blogposts are welcome) with upvotes.) UPDATE A couple items of note: -We are not currently using OWA (currently only the admins), but it may become more of a consideration with iOS devices. -We do have a small number of Blackberries in the environment (< 10%). -In addition to the standard Exchange connectors, we have a third-party connector for Captaris RightFax integration.

  Read the article

• Best tool for monitoring backups, etc. and trending statstics from that data

  - by Randy Syring

  I have done some research on nagios, opennms, and zenoss but am not confident that I have found what I am looking for. The main driving force for me right now is being able to monitor backups. This includes mysql, mssql, and eventually some file system backups. We have a tool that wraps the backup process for these different systems and collects statistics. So, items like: number of databases backed up size of db backup file size of db backup file compressed time to make backup time to zip file I want to be able to A) have notifications if the jobs are not run according to schedule B) be able to set thresholds on the statistics which would trigger notifications C) I want to be able to trend and graph the statistics I am planning on sending this information to the monitoring application through an HTTP POST. Or, the monitoring application could pull it from a log file as well. However, we will have other processes with other "arbitrary" (from the monitoring system's perspective) statics that will want to monitor and trend, so flexibility is very important. The tool or tools should also be able to do general monitoring and trending of network interfaces, server load, etc. Once we get the backup monitoring in place, we will want to include those items as well. Thanks.

  Read the article

• Bandwidth Suggestion

  - by Campo

  I have been asked to analyze the bandwidth usage of a company and make a recommendation for upgrading their Internet connection(s). Here is the layout 3 DLS lines so it is 3x(6 Down, 1 Up Each) into a load balancer out to the office's network. 30 VOIP phones run on a T1 (1.5 Down, 1.5 Up) The users at the company are heavily uploading. It is my suspicion that the issue in slowdown is being cause by multiple people uploading and others not being able to get requests out for even simple http requests. My initial idea is to get them a fiber line with a 10 down and 10 up. What do others think on this plan? Will that be enough to host their network traffic? What do I do about the VOIP line afterward? The fiber is expensive and I know the T1 does a great job for their VOIP so I do not want to suggest a DSL line because I know it may not be sufficient. I would also like to save them some money if I can. Maybe even get a faster fiber line and forgo the T1. Though I know their load balance/switch can only handle 20MB/S throughput. Looking for some confirmation/suggestions on my plan. I am planning on going in to get some real diagnostic numbers. Any suggestions on software to use for that? Preferably Windows software.

  Read the article

• Vlans and subinterfaces

  - by Adeodatus

  I've inherited a moderate size network that I'm trying to bring some sanity to. Basically, its 8 public class Cs and a slew of private ranges all on one vlan (vlan1, of course). Most of the network is located throughout dark sites. I need to start separating some of the network. I've changed the ports from the main cisco switch (3560) to the cisco router (3825) and the other remote switches to trunking with dot1q encapsulation. I'd like to start moving a few select subnets to different vlans. To get some of the different services provided on our address space (and to separate customers) on to different vlans, do I need to create a subinterface on the router for each vlan and, if so, how do I get the switch port to work on a specific vlan? Keep in mind, these are dark sites and geting console access is difficult if not impossible at the moment. I was planning on creating a subinterface on the router for each vlan then setting the ports with services I want to move to a different vlan to allow only that vlan. Example of vlan3: 3825: interface GigabitEthernet0/1.3 description Vlan-3 encapsulation dot1Q 3 ip address 192.168.0.81 255.255.255.240 the connection between the switch and router: interface GigabitEthernet0/48 description Core-router switchport trunk encapsulation dot1q switchport mode trunk show interfaces gi0/48 switchport Name: Gi0/48 Switchport: Enabled Administrative Mode: trunk Operational Mode: trunk Administrative Trunking Encapsulation: dot1q Operational Trunking Encapsulation: dot1q Negotiation of Trunking: On Access Mode VLAN: 1 (default) Trunking Native Mode VLAN: 1 (default) Administrative Native VLAN tagging: enabled Voice VLAN: none Administrative private-vlan host-association: none Administrative private-vlan mapping: none Administrative private-vlan trunk native VLAN: none Administrative private-vlan trunk Native VLAN tagging: enabled Administrative private-vlan trunk encapsulation: dot1q Administrative private-vlan trunk normal VLANs: none Administrative private-vlan trunk private VLANs: none Operational private-vlan: none Trunking VLANs Enabled: ALL Pruning VLANs Enabled: 2-1001 Capture Mode Disabled Capture VLANs Allowed: ALL Protected: false Unknown unicast blocked: disabled Unknown multicast blocked: disabled Appliance trust: none So, if the boxen hanging off of gi0/18 on the 3560 are on an unmanaged layer2 switch and all within the 192.168.0.82-95 range and are using 192.168.0.81 as their gateway, what is left to do, especially to gi0/18, to get this working on vlan3? Are there any recommendations for a better setup without taking everything offline?

  Read the article

• Feasibility of Windows Server 2008 DFS replication over WAN link

  - by CesarGon

  We have just set up a WAN link that connects two buildings in our organisation. The link is provided by a 100-Mbps point to point line. We have a Windows Server 2008 R2 domain controller on each side of the link. Now we are planning to set up DFS for file services across the organisation. The estimated data volume is over 2 TB, and will grow at approximately 20% annually. My idea is to set up a file server in each building and install DFS so that all the contents stay replicated over the 100-Mbps link. I hope that this will ensure that any user will be directed to the closest (and fastest) server when requesting a file from the DFS folders. My concern is whether a 100-Mbps WAN link is good enough to guarantee DFS replication. I've no experience with DFS, so any solid advice is welcome. The line is reliable (i.e. it doesn't crash often) and our data transfer tests show that a 5 MB/sec transfer rate is easily achieved. This is approximately 40% of the nominal bandwidth. I am also concerned about the latency. I mean, how long will users need to wait to see one change on one side of the link after the change has been made on the other side. My questions are: Is this link between networks a reliable infrastructure on which to set up DFS replication? What latency times would be typical (seconds, minutes, hours, days)? Would you recommend that we go for DFS in this scenario, or is there a better alternative? Many thanks.

  Read the article

• DAS vs SAN storage for serving 2 to 4 nodes

  - by Luke404

  We currently have 4 Linux nodes with local storage, arranged in two active/passive pairs with storage mirrored using DRBD, running virtual machines (actually using Xen Hypervisor) for typical hosting workloads (mail, web, a couple VPS, etc.). We're approaching the (presumed) maximum IOPS of those servers, and we're planning to migrate to an external storage solution with two active nodes, with capacity for up to four active nodes. Since we're an all-Dell shop I've done some research and found the MD3200 / MD3200i products should be the ones we're looking for. We are pretty sure we won't be attaching more than 4 hosts on a single storage and I'm wondering if there is any clear advantage for one or the other. In theory I should be able to attach 4 SAS hosts to a single MD3200 (single links on a single controller MD3200, or dual redundant SAS links from each host to a dual-controller MD3200), or 4 iSCSI hosts to a single MD3200i (directly on its 4 GigE ports without any switch, again with dual links for the dual controller option). Both setups should let us implement live VM migration since all hosts can access all the LUNs at the same time, and also some shared filesystem like GFS2 or OCFS2. Also, both setups should allow full redundancy of the whole system (assuming dual controllers in the storage). One difference I can see is that the DAS solution is actually limited to 4 hosts while the iSCSI one should be able to grow to more hosts (adding two GigE switches to the mix). One point for the iSCSI solution is that it would allow us to start out with our current nodes and upgrade them at a later time (we can't add other SAS controllers, but they already have 4 GigE ports each). With the right (iSCSI|SAS) controllers I should be able to connect diskless nodes and boot them off the external storage which I think is a good thing (get rid of any local storage). On the other hand, I would have thought the SAS one to be cheaper but it seems like an MD3200 actually costs a little less than an MD3200i (?) (please note: I've used Dell gear in my examples since that's what we're looking for but I assume the same goes with other vendors) I would like to know if my assumptions above are correct, and if I'm missing any important difference between the two setups.

  Read the article

• Ram question in VMware Server 2

  - by ToreTrygg

  Hi, I understand from the VMware Server 2 documentation that VMware Server 2 is capable of running a 64-bit guest OS underneath a 32-bit host OS, as long as the hardware running the box is 64-bit capable. Here's my situation. We currently have an underutilized XEON X3220 Quad Core 64bit Server, running Server 2003, 32-bit and 2gb of RAM (the motherboard is capable of 8gb ram). The server is currently used mainly for file and print services. It is also running Active Directory, Novell eDirectory and Groupwise 6.5. We are planning a micration to Microsoft Exchange, so the Novell eDirectory and Groupwise services will eventually be purged from this box, leaving only Active Directory, File and Print services. Being that this server is underutilized we are hoping to save hardware costs and virtualize our new Exchange investment. My question is this. Will VMware allow access to the "invisible" extra memory that Windows 32-bit won't see. Meaning, if we increase the full amount of system ram to 8gb (yes, I know the 32-bit host OS will only see a maximum of 4gb), will I be able to assign maybe 5gb to the new Server 2008 64-bit OS running Exchange and leave 3gb for the Guest OS (or maybe even a 6, 2 split). The second part of that would be, would it be better to just convert the main OS currently running to an image, convert the machine itself to ESXi and run both OSes as images under ESXi. Downtime for this box is critical, so my preference is most definitly with the first option because it presents very minimal downtime. Doing the second would make downtime quite a few hours to image the machine and then convert the image to a VMware Image.

  Read the article

• Are there any open source reseller packages?

  - by Tom Wright

  My department has just been given the right/responsibility to manage our own VPS. The idea being that the bureaucracy will be less for the many small web projects we run. Since each project will be managed by a different team, I was planning on approaching a shared hosting model. Are there any free pieces of software that would help automate the provision of resources each time a team request a new project? Most of the projects have identical requirements - basically LAMP - so it would be these resources that I would want provisioning (and de-provisioning, if that is a word) automatically. Ideally, there would also be a way to hook it into our LDAP authentication backend too, though I could probably make this sort of modification if necessary. Since we won't be charging our "client" however, we won't need the ability to generate invoices, handle payments, etc. etc. EDIT: Sample workflow Login authenticated against LDAP Username checked against admin group (not on central LDAP) Click 'new project' and enter project name User created on VPS with project name as username Apache virtual host created and subdomain (using project name) allocated FTP & MySQL users created

  Read the article

• split virtualization design based on environment or server role?

  - by Dan

  I'm setting up the server environment for a new software development group, which will include 4 test environments. These are web applications, so each environment will have an application server and a database server. I'm planning on buying two physical servers (e.g. 6-core CPU each with 12GB or so of RAM), and I'm thinking virtualization is appropriate here. With that in mind, I've thought of a couple ways that I could organize the virtualization strategy: - Separated by server role: Server 1 has all the application servers, each in their own guest VM. Server 2 has all the databases. OR - Separated by environment: Server 1 has a VM for two of the environments, with the VM containing both the app server and the database server. Server 2 would also contain two test environments, with the same style (app server and database in same VM). The advantages I see with all the app servers on one server and all the databases on another server is that I could probably be more efficient with the database server (one instance running multiple databases). But the other option seems easier to manage (archives/restorations would be contained in a single VM). Any recommendations? TIA.

  Read the article

• RAM ok in memtest86+ == RAM ok after wake from sleep?

  - by twon33

  I have a Windows XP (32-bit) system that appears stable in normal operation, but was repeatably freezing (hard lock, no BSOD) a minute or so after waking from S3 sleep. Some Googling against the motherboard model and memory manufacturer suggested that I might need to bump up the memory voltage, so I tried it and it now seems to resume without freezing. However, I don't really trust it and I'd like to validate that it's actually stable, especially after resuming from sleep. I've run Prime95 for a few hours with no issues, and am planning an overnight run of Memtest86+, which I expect to pass because the system has been solid whenever I've run it without putting it to sleep. Does something like Memtest86+ exist that actually invokes S3 sleep during operation? Clearly it would need an operator to wake the computer to resume testing, but I don't think I've ever heard of a memory test tool that can do this. Alternately, am I wasting my time? Should a clean bill of health from Memtest86+ indicate stability regardless of whether sleep is involved, or, conversely, does my original problem indicate that Memtest86+ would have failed eventually with the stock voltage if I'd run it, sleep or not?

  Read the article

• replacing buffalo lonkstations with FreeNAS, overall backup strategy, am I on the right path?

  - by Shreko

  We've been using 2 Buffalo LinkStations of 320Gb each for shared directory and employee's server storage (around 20 employees). So only documents (word, excel, cad drawings etc.) and database backup of the main application server (ERP, Accounting) 1 buffalo box serves as a main one, located at the server room, next to the main application server and the other buffalo box is located on the opposite side of the building (for fire protection) in a secure storage room and backs up the first one. We also have several external HDs that backs up everything from the buffalo box for an offsite backup. After 3.5 years of using these, capacity is a main limitation, I'm planning a replacement and would like to use FreeNAS (we already use monowall with great success). I would like to keep it simple and continue similar setup, building two low power boxes with 1 hd (2Tb) each. Is low power atom mobo OK? Not sure about HDs? I've read on this site somebody mentioning more seagate ES2 as more reliable and better performing. How would those eco/green drives compare. We've been pretty happy with speed of Buffalo boxes and I don't want my users to notice any slowdown. Any suggestion?

  Read the article

• Blocking HTTPS and P2P Traffic

  - by Genboy

  I have a Debian server running at the gateway level on a LAN. This runs squid for creating block lists of websites - for eg. blocking social networking on the LAN. Also uses iptables. I am able to do a lot of things with squid & iptables, but a few things seem difficult to achieve. 1) If I block facebook through their http url, people can still access https://www.facebook.com because squid doesn't go through https traffic by default. However, if the users set the gateway IP address as proxy on their web browser, then https is also blocked. So I can do one thing - using iptables drop all outgoing 443 traffic, so that people are forced to set proxy on their browser in order to browse any HTTPS traffic. However, is there a better solution for this. 2) As the number of blocked urls increase in squid, I am planning to integrate squidguard. However, the good squidguard lists are not free for commercial use. Anyone knows of a good squidguard list which is free. 3) Block yahoo messenger, gtalk etc. There are so many ports on which these Instant Messenger softwares work. You need to drop lots of outgoing ports in iptables. However, new ports get added, so you have to keep adding them. And even if your list of ports is current, people can still use the web version of gtalk etc. 4) Blocking P2P. Haven't been able to figure out how to do this till now.

  Read the article

• Adventures in Drupal multisite config with mod_rewrite and clean urls

  - by moexu

  The university where I work is planning to offer Drupal hosting to staff/faculty who want a Drupal site. We've set up Drupal multisite with clean urls and it's mostly working except for some weird redirects. If you have two sites where one is a substring of the other then you'll randomly be redirected to the other site. I tracked the problem to how mod_rewrite does path matching, so with a config file like this: RewriteCond %{REQUEST_URI} ^/drupal RewriteCond %{REQUEST_FILENAME} !-f RewriteCond %{REQUEST_FILENAME} !-d RewriteRule ^(.*)$ /drupal/index.php?q=$1 [last,qsappend] RewriteCond %{REQUEST_URI} ^/drupaltest RewriteCond %{REQUEST_FILENAME} !-f RewriteCond %{REQUEST_FILENAME} !-d RewriteRule ^(.*)$ /drupaltest/index.php?q=$1 [last,qsappend] /drupaltest will match the /drupal line and all of the links on the /drupaltest page will be rewritten to point to /drupal. If you put the end of string character ($) at the end of each rewrite condition then it will always match on the correct site and the links will always be rewritten correctly. That breaks down as soon as a user logs in though because the query string is appended to the url so just the base url will no longer match. You can also fix the problem by ordering the sites in the config file so that the smallest substring will always be last. I suggested storing all of the sites in a table and then querying, sorting, and rewriting the config file every time a Drupal site is requested so that we could guarantee the order. The system administrator thought that was kludgy and didn't address the root problem. Disabling clean urls should also fix the problem but the users really want them so I'd prefer to keep them if possible. I think we could also fix it by using an .htaccess file in each site to handle the clean url rewriting but that also seems suboptimal since it will generate a higher load on the server and the server is intended to host the majority of the university's external facing web content. Is there some magic I can do with mod_rewrite to get it to work? Would another solution be better? Am I doing something the wrong way to begin with?

  Read the article

• Exchange 2010 CAS Removal == Broken???

  - by Doug

  Hi there, I recently upgraded to exchange 2010 and have a setup with 2 of my servers running CAS roles - EXCH01, EXCH02 EXCH02 just happens to also have a mailbox role where a lot of the users sit EXCH01 is my front facing CAS server, and is facing the net with SSL etc and incoming mail moving through it as a hub transport layer server as well. As i was trying to lean things out in my VM environment i removed the CAS role from EXCH02 and all hell broke loose. All the mail users that have a mailbox on EXCH02 had their homeMTA set to a deleted items folder in AD and so did their msExchHomeServer properties. After a complete battle i manually fixed these issues to the oldvalues, and in the mean time reinstalled CAS on EXCH02 (management was going nuts with out OUTLOOK working so i just put things back the way they were in a hurry.) I must add as a strange thing on the side, that before i reset these to point at EXCH02 i tried EXCH01 and it failed. I still want to remove the CAS role from EXCH02 as it should really not have it (error on install/planning on my part) and would have thought that this would not cause the issues it did, i assumed that the fact that there was another CAS server in the admin group all would be good. Was i wrong in my assumption? and what can i do to complete this successfully the second time round? Do i need to rehome all the mailboxes to the CAS server? is this a bug in the role uninstall?

  Read the article

• Network Load Balancing and AnyCast Routing

  - by user126917

  Hi All can anyone advise on problems with the following? I am planning on installing the following setup on my estate: I have 2 sites that both have a large amount of users. Goals are to keep things simple for the users and to have automatic failover above the database level. Our Database will exist at the primary site and be async mirrored to the secondary site with manual failover procedures.The database generate sequential ID's so distributing it is not an option. I plan to site IIS boxes at both sites with all of the business logic on them and heavy operations. The connections to SQL will be lightweight and DB reads will be cached on IIS. On this layer I plan to use Windows network load balancing and have the same IP or IPs across all IIS boxes at both sites. This way there will be automatic failover and no single point of failure. Also users can have one web address regardless of which site they are in automatically be network load balanced to their local IIS. This is great but obviously our two sites are on different subnets and as this will be one IP address with most of our traffic we can't go broadcasting everything across the link between the sites. To solve this problem we plan to use AnyCast routing over our network layer to route the traffic to the most local box that is listening which will be defined by the network load balancing. Has anyone used this setup before? Can anyone think of any issues with this? Also some specifics I can't find anywhere at the moment. If my Windows box is assigned an IP and listening on that IP but network load balancing is not accepting specific traffic then will AnyCast route away from that? Also can I AnyCast on a socket level?

  Read the article

• What is the peak theoretical WiFi G user density? [closed]

  - by Bigbio2002

  I've seen a few WiFi capacity planning questions, and this one is related, but hopefully different enough not to be closed. Also, this is related specifically to 802.11g, but a similar question could be made for N. In order to squeeze more WiFi users into a space, the transmit power on the APs need to be reduced and the APs squeezed closer together. My question is, how far can you practically take this before the network becomes unusable? There will come a point where the transmit power is so weak that nobody will actually be able to pick up a connection, or be constantly roaming to/from APs spaced a few feet apart as they walk around. There are also only 3 available channels to use as well, which is a factor to consider. After determining the peak AP density, then multiply by users-per-AP, which should be easier to find out. After factoring all of this in and running some back-of-the-envelope calculations, I'd like to be able to get a figure of "XX users per 10ft^2" or something. This can be considered the physical limit of WiFi, and will keep people from asking about getting 3,000 people in a ballroom conference on WiFi. Can anyone with WiFi experience chime in, or better yet, provide some calculations for a more accurate figure? Assumptions: Let's assume an ideal environment with no reflection (think of a big, square, open room, with the APs spaced out on a plane), APs are placed on the ceiling so humans won't absorb the waves, and the only interference are from the APs themselves and the devices. As for what devices specifically, that's irrelevant for the first point of the question (AP density, so only channel and transmit power should matter). User experience: Wikipedia states that Wireless G has about 22Mbps maximum effective throughput, or about 2.75MB/s. For the purpose of this question, anything below 100KB/s per user can be deemed to be a poor user experience. As for roaming, I'll assume the user is standing in the same place, so hopefully that will be a non-issue.

  Read the article

• Did chkdsk make it harder to restore files?

  - by neyl

  My friend asked me to try and fix his loaded Sansa Clip + which wasn't playing. After opening it in MSC mode I discovered that the Music directory was empty and total of all files was only a few MB. However Disk properties showed me that it was 7Gb full. I then ran Tools - Error Checking and Windows dutifully informed me that disk was corrupt and I should run again Allowing Windows to Fix Errors. I did that and it told me everything was fixed and that all files were placed in FOUND.000 Dir. FOUND.000 was about 7.5 GB with FILE0000-1546 . CHK. (I am aware of methods like ChkBack to scan and convert to mp3 etc BUT Original filenames and structure needed!) Now I started getting worried that I made things worse! I have plenty of experience with Data Recovery Programs - Recuva, Restore My Files etc. and I was anyhow planning to use them to scan the drive. But NOW after CHKDSK "fixed" the drive maybe it modified critical FAT information vital for data recovery. So I run these programs and 0!!!. No trace of files! I tried a ton of Recovery Programs with same results TILL EaseUS Data Recovery Wizard found all files and I purchased program for $55! My Question In your opinion - did running CHKDSK with automatic fixing of errors make matters worse (i.e. many data recovery progs. didn't find a trace and they would have done if not for chkdsk) or was the filesystem too corrupt anyhow for regular File Recovery Progs.? If I would be a Professional - would I be responsible for running CHKDSK - automatic Fixing. Do you know of a better Data Recovery Program than EaseUs Data Recovery wizard - According to my experience I haven't found better!? Thanks

  Read the article

• Best practices for thin-provisioning Linux servers (on VMware)

  - by nbr

  I have a setup of about 20 Linux machines, each with about 30-150 gigabytes of customer data. Probably the size of data will grow significantly faster on some machines than others. These are virtual machines on a VMware vSphere cluster. The disk images are stored on a SAN system. I'm trying to find a solution that would use disk space sparingly, while still allowing for easy growing of individual machines. In theory, I would just create big disks for each machine and use thin provisioning. Each disk would grow as needed. However, it seems that a 500 GB ext3 filesystem with only 50 GB of data and quite a low number of writes still easily grows the disk image to eg. 250 GB over time. Or maybe I'm doing something wrong here? (I was surprised how little I found on the subject with Google. BTW, there's even no thin-provisioning tag on serverfault.com.) Currently I'm planning to create big, thin-provisioned disks - but with a small LVM volume on them. For example: a 100 GB volume on a 500 GB disk. That way I could more easily grow the LVM volume and the filesystem size as needed, even online. Now for the actual question: Are there better ways to do this? (that is, to grow data size as needed without downtime.) Possible solutions include: Using a thin-provisioning friendly filesystem that tries to occupy the same spots over and over again, thus not growing the image size. Finding an easy method of reclaiming free space on the partition (re-thinning?) Something else? A bonus question: If I go with my current plan, would you recommend creating partitions on the disks (pvcreate /dev/sdX1 vs pvcreate /dev/sdX)? I think it's against conventions to use raw disks without partitions, but it would make it a bit easier to grow the disks, if that is ever needed. This is all just a matter of taste, right?

  Read the article

• How to place a virtual machine in DMZ?

  - by Giordano

  I have an Ubuntu 12.04 server running few virtual machines with KVM. I would like to expose some of these virtual machines on the internet, to make it possible for customers to test the products we're developing and make available other products for demo purposes. One of the server NICs is configured with a public IP. However before exposing anything on the web I would like to be sure that if one of the virtual machines get compromised, the attacker doesn't reach the rest of the hosts. What I would like to do is to put these virtual machines into a DMZ. These are the steps I'm planning to do: Create a tap interface in the virtualization host (let's say tap1) Create a bridge using tap1 and give it an IP in a subnet separate from the other hosts. Let's say 10.0.0.1 Attach the DMZ virtual machines to the bridge and configure their IP statically (10.0.0.2, 10.0.0.3, etc...) Using UFW, forbid any traffic from 10.0.0.0/24 to any of the internal hosts, allow the traffic from the internal hosts towards 10.0.0.0/24 and expose the virtual machines on the web using port forwarding. Do you think this setup is safe? Can you suggest any improvement or a better/safer approach? Thanks in advance!

  Read the article

• Varnish, Nginx, Apache, APC, Meteor, Cpanel & Wordpress On A Single Server, Any Good?

  - by Aahan

  Yes, I have read many close questions, but I needed a specific answer and hence this question. First, these are my new server specifications: Linux Server (CentOS), Intel Xeon 3470 Quad Core (2.93GHz x 4) processor, 4 GB DDR3 Memory, 1TB Hard Disk Space, 10 TB Bandwidth and 9 Dedicated IPs. AIM: To speed up my wordpress blog + Increase server's capacity to handle heavy load PLAN: This is how I am planning to setup my server - - VARNISH (in the front, to cache server responses) NGINX (to effectively handle static content & overcome the C10k problem) APACHE (behind Nginx, to effectively deliver dynamic content) APC (PHP page, database & object caching) CPANEL (which requires Apache, and I require it) WORDPRESS W3 TOTAL CACHE (caching plugin for Wordpress). So , will the setup work? Have anyone tried it? Please shower your thoughts and knowledge. NOTE: I can't do without Apache because I am used to that .htaccess & Cpanel stuff. So, it's not any option. All others are options. Please try to help. I hope I am clear in what I wanted to ask.

  Read the article

• Process to replace motherboard and keep CPU

  - by jolivier

  My motherboard has been diagnosed with the Sandy Bridge issue (http://vip.asus.com/eservice/changeSandybridge_MB.aspx?slanguage=en-us) so I am asked by my reseller to send back my motherboard to have a new one compatible with the previous one. My problem is that I have a not cheap Intel CPU currently on it, with its standard heatsink/fan. I would obviously like to keep it to plug it on the new motherboard. I am quite woried about the thermal paste. I was planning to: Remove the CPU and the HSF together (I think they are sticked to each other). Try to separate the CPU and the HSF (I'm not sure how) Clean both of the surfaces When the new motherboard is here, put the CPU back on it. Have new thermal paste to put again on the CPU, put it on the CPU Add the HSF again Do you see any problem about this process? Recommendations? Is it possible to keep the CPU and the HSF together for the whole process or is it impossible to plug the CPU back on the new motherboard in this case? Thanks in advance for your answers. Olivier

  Read the article

< Previous Page | 114 115 116 117 118 119 120 121 122 123 124 125  | Next Page >