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  • How to prevent eMule from jamming up the router?

    - by the searcher
    Usually, when eMule is started, after some time, I find that the router is jammed, so the internet connection on that computer stopped working, or it seemed to be waiting for some port to be freed up before it can connect to a website. This sometimes affect even other PCs or Macs using the same router. Is there a way to prevent eMule from hogging too much resource or ports? I see that there is under Options -> Connection "Max Sources/File" and a "Connection Limits - Maximum Connections". Right now I set them to really low numbers: the first to 120 and the second to 200, but what are good numbers to fill in there so that it can work well without jamming up the router or use up the network resource of the PC or Mac? Or could it be that the number of files that are "Waiting" is too high, and used up too much resource? (If so, can emule automatically limit the number to 10 or 20 to prevent using too much resource?) (This happened before on Linksys router, Netgear router, and the AT&T U-verse router.)

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  • Short, intermittent USB port timeouts

    - by jacobsee
    I have a data acquisition application controlled by a Windows PC. I am using an Intel Desktop Board DH67CL motherboard. This has 6 USB2 ports along with 2 of the new blue USB3 ports. The DAQ instrument connects via USB to the computer. Roughly once every day or two there is a short communication glitch with the USB that causes the instrument to disconnect briefly and then reconnect. This is logged so I know whenever it happens. Occasionally it will cause the data acquisition to stop. I've verified that the glitches will go away if I use the USB3 ports, or if I use a PCI add-on card with USB ports. So it seems that there is something going on with these built-in USB2 ports on this motherboard. I haven't yet had a chance to test with other motherboards. My question: what could be causing these glitches and how to get rid of them for this board, or is there a better motherboard to use? We have standardized on the DH67CL because it's inexpensive, has 3 PCI slots that we need, and is readily available. We don't need the power of higher-end server boards but reliability is important. Thanks. Update: This problem has been reproduced many times on different hardware, though we always use the same model of motherboard (DH67CL) and power supply (Antec EA-430D). I don't think the power requirements are very high but will check on that.

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  • Which CPU for XEN - LAMP testbed - Budget

    - by deploymonkey
    Dear serverfault knowledgeables, im in a decision dilemma right now, which I can't resolve due to lack of hands on experience. I need to build a testbed for basically virtualizing a LAMP application (os'ses not yet decided) including server side calculations. I'll opt for XEN since it seems better supported by cloud hosters at the moment. The hardware is for a proof of concept for a startup doing saas and might be used for closed live alpha/beta later on. After testing, the testbed might be a) deployed as a colocated white box server b) used as workstation Single socket is enough. We want to have ECC memory for reliability, this excludes most of the consumer line at intel. If intel CPU, then threaded cpu (HT) is preferred have at least 16 gig ram If justified by price and reliability is not too bad, a high quality desktop MB instead of a server MB would be worth a try It came down to the opteron 6128 vs. the xeon 5620 for me after a lot of research, but I don't necessarily have to be right. Which CPU is preferrable, concerning TCO (MB price, power requirements 24/7...) , Opteron 6128 or Xeon 5620? Which one offers better performance in real world applications? (Do You have any other suggestions I probably overlooked?) Thank You for Your consideration

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  • Log shipping on select tables.

    - by Scott Chamberlain
    I know I am most likely using incorrect terminology so please correct me if I use the wrong terms so I can search better. We have a very large database at a client's site and we would like to have up to date copies of some of the tables sent across the internet to our servers at our office. We would like to only copy a few of the tables because the bandwidth requirement to do log shipping of the entire database (our current solution) is too high. Also replication directly to our servers is out of the question as our servers are not accessible from the internet and management does not want to do replication (more on that later). One possible Idea we had is to do some form of replication on the tables we need to another database on the same server and do log shipping of that second smaller database but management is concerned that the clients have broken replication (it was between two servers on their internal network however) on us in the past and would like to stay away from it if possible. Any recommendations would be greatly appreciated. If using some form of replication is the only solution, I am not against replication, I just need compelling arguments to convince management to do it. This is to be set up on multiple sites that are running either Sql2005 or Sql2008 we will have both versions on our end to restore the data to so that is not a issue. Thank you.

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  • What is the best private cloud storage setup

    - by vdrmrt
    I need to create a private cloud and I'm searching for the best setup. These are my 2 most important requirements 1. Disk and system redundant 2. Price / GB as low as possible The system is going to be used as backup setup which will receive data 24/7 over SFTP and rsync. High throughput is not that important. I'm planning to use glusterfs and consumer grade 4TB hard-drives. I have worked out 3 possible setups 3 servers with 11 4TB HDD Setup up a replica 3 glusterfs and setup each hard drive as a separate ext4 brick. Total capacity: 44TB HDD / TB ratio of 0.75 (33HDD / 44TB) 2 servers with 11 4TB HDD The 11 hard-drives are combined in a RAIDZ3 ZFS storage pool. With a replica 2 gluster setup. Total capacity: 32TB (+ zfs compression) HDD / TB ratio of 0.68 (22HDD / 32TB) 3 servers with 11 4TB consumer hard-drives Setup up a replica 3 glusterfs and setup each hard-drive as a separate zfs storage pool and export each pool as a brick. Total capacity: 32TB (+ zfs compression) HDD / TB ratio of 0.68 (22HDD / 32TB) (Cheapest) My remarks and concerns: If a hard drive fails which setup will recover the quickest? In my opinion setup 1 and 3 because there only the contents of 1 hard-drive needs to be copied over the network. Instead of setup 2 were the hard-drive needs te be reconstructed by reading the parity of all the other harddrives in the system. Will a zfs pool on 1 harddrive give me extra protection against for example bit rot? With setup 1 and 3 I can loose 2 systems and still be up and running with setup 2 I can only loose 1 system. When I use ZFS I can enable compression which will give me some extra storage.

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  • Apache suddenly very slow on http and faster on https

    - by hsnm
    Background: I have Apache 2 running on ubuntu. There is a low usage on it and mostly being accessed for a web service URL from mobile apps. It was working fine until I installed SSL certificates. I now have both http and https. When I access the server using https, I get a fairly quick response (but probably not as fast as before). When I use http, it's so slow. What I tried: From this post: I curl localhost from the host and it takes some time, meaning there is no routing issue. The server runs on Amazon EC2 instance and is managed by me only. Also: I see that Apache once running, creates the maximum number of processes it is allowed to, which was not the case before. I lowered the MaxClients to 20 and I think I'm getting faster responses but it still takes over a minute and I always have MaxClients Apache processes. dmesg returns many [ 1953.655703] TCP: Possible SYN flooding on port 80. Sending cookies. When I netstat I get many entries with SYN_RECV. Possibly a DDoS attack? From EC2's monitoring diagrams I see a pattern of high "Maximum Network In (Bytes)" since 2 days ago. By the way the server is still being tested, the actual traffic is very low and not consistent. I tried to go with this solution to limit incoming connections using iptables, still no luck, but I'm trying. Question: What could be the problem? Is this a DDoS attack?

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  • Help, my CentOS servers keep going down , No route to host after a random uptime

    - by user249071
    Hello , I have a couple of Centos linux servers, that have a very simple task, they run nginx + fastcgi for php , and some NFS mounts between them, readonly They have some RPC commands to start some downloading processes with wget, nothing fancy , from a main server, but their behavior is very unstable, they simply go down, we tried to monitor ram , processor usage, even network connections, they don't load up so much, max network connections up to... 250 max, 15% processor usage and memory , well, doesn't even fill up, 2.5GB from 8GB max , I have no ideea why can a linux server go down like that, they aren't even public servers, no domain names installed no public serving, for sites. The only thing that I've discovered was that if i didn't restart the network service every couple of hours or so... the servers were becoming very slow, starting apps very slow, but not repoting a high usage of resources...Maybe Centos doesn't free the timeout connections, or something like that...It's based on Red Hat right? I'm not a linux expert , but I'm sure that there are a few guys out there that can easily have an answer to this , or even have some leads to what i can do ... I haven't installed snort, or other things to view if we have some DOS attacks, still the scheduled script that restarts the network each hour should put the system back online, and it doesn't.... Thank you in advance

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  • i7 Windows 7 laptop or Macbook Pro 15" (For making 3D model and Animation)

    - by sppdhs
    Hi everyone, I'm thinking of buying a new laptop as my current one will be 5 years old next year and it currently gives me a blue screen everytime I run a heavy software to make 3D models and animation. Question is: Should I buy Macbook Pro or a Windows 7 laptop? I tried to research and some say that Windows would be better, especially because you can buy a very high spec laptop with cheaper price. While some other say Macbook Pro is the better choice as it can run bootcamp with windows 7 100% performance on every software even though it's a mac. Is this true? Which one is actually better? Btw, the software that I usually use is 3Ds Max, Maya, and ZBrush. To note as well, I have never used a Mac before. I've checked around some stores and budget wise, I'll need around AU$3000+ to buy a Macbook pro, and AU$2000+ to buy a windows laptop. Quite a big difference in price range. Thanks in advance for your help.

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  • Can't mount Linux usb disk. It just create /dev/sg device but no /dev/sd

    - by MTilsted
    I have a Corsair R60 ssd disk which is a disk with both sata and usb connectors. But the usb thing seems to be a bit non-standard, or maybe its just my fedora linux. When I insert the disk using a usb cabel to a running Fedora 14 linux system, a device called /dev/sg3 is added but that is all. No new /dev/sd* device is created so I can't mount the disk. If I look at cat /proc/scsi/sg/device_strs I get ATA Hitachi HTS54321 FB2O HL-DT-ST DVDRAM GSA-T50N RP05 Seagate Desktop 0130 Corsair CSSD-R60GB2 So the disk is there. (The last entry) but my linux will for some reason not see it as a usb hard disk. When I insert other usb disks they work fine. It is only this specific disk which causes problems. I have tried on 3 different computers with the same result. A hint to the problem may be that if I add the disk to a windows system(With usb) the disk is called "A fixed disk" and not a portable disk as expected. The disk works fine with linux If i connect it with the sata cabel, but I would really like to have it working with usb too. (To mount it on computers without sata). Added: I did try to mount /dev/sg3 but mount say that its not a block device. (File say Its a character special device). Added output from dmesg: [ 97.454073] usb 7-1: USB disconnect, address 2 [ 105.913055] hub 2-0:1.0: unable to enumerate USB device on port 3 [ 107.048054] usb 2-3: new high speed USB device using ehci_hcd and address 5 [ 107.162900] usb 2-3: New USB device found, idVendor=1b1c, idProduct=1ab8 [ 107.162903] usb 2-3: New USB device strings: Mfr=1, Product=2, SerialNumber=5 [ 107.162906] usb 2-3: Product: CSSD-R60GB2 [ 107.162908] usb 2-3: Manufacturer: Corsair [ 107.162910] usb 2-3: SerialNumber: 10111441000000990069 [ 107.167651] scsi7 : usb-storage 2-3:1.0 [ 108.195543] scsi 7:0:0:0: Direct-Access Corsair CSSD-R60GB2 PQ: 1 ANSI: 0 [ 108.197732] scsi 7:0:0:0: Attached scsi generic sg3 type 0

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  • Hide/Replace Nginx Location Header?

    - by Steven Ou
    I am trying to pass a PCI compliance test, and I'm getting a single "high risk vulnerability". The problem is described as: Information on the machine which a web server is located is sometimes included in the header of a web page. Under certain circumstances that information may include local information from behind a firewall or proxy server such as the local IP address. It looks like Nginx is responding with: Service: https Received: HTTP/1.1 302 Found Cache-Control: no-cache Content-Type: text/html; charset=utf-8 Location: http://ip-10-194-73-254/ Server: nginx/1.0.4 + Phusion Passenger 3.0.7 (mod_rails/mod_rack) Status: 302 X-Powered-By: Phusion Passenger (mod_rails/mod_rack) 3.0.7 X-Runtime: 0 Content-Length: 90 Connection: Close <html><body>You are being <a href="http://ip-10-194-73-254/">redirect ed</a>.</body></html> I'm no expert, so please correct me if I'm wrong: but from what I gathered, I think the problem is that the Location header is returning http://ip-10-194-73-254/, which is a private address, when it should be returning our domain name (which is ravn.com). So, I'm guessing I need to either hide or replace the Location header somehow? I'm a programmer and not a server admin so I have no idea what to do... Any help would be greatly appreciated! Also, might I add that we're running more than 1 server, so the configuration would need to be transferable to any server with any private address.

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  • CPU operating temperature ranges

    - by osij2is
    I have an AMD Phenom II 960T with 2 cores unlocked for a total of 6 cores. I don't overclock at all. I have a Arctic Cooling ACALP64 Heatsink/Fan installed. I'm currently running ESXi 5.0 so I have to go into the BIOS to read the CPU temperatures, which at idle seem to be in the 71-74C range. To me, this is pretty high, but I cannot find any official temperature ranges that AMD says the CPU can work well within. There seems to be a lot of questions on superuser and numerous forums around CPU temperatures but no one seems to have a clear consensus as to what the manufacturer temperature ranges are for specific CPUs. I've tried searching through AMDs site to no avail. At this point, I'd be willing to shut off the 2 extra cores if it keeps the heat down but until I get some sort of tolerance or range for temperature, I have no idea if the CPU is being damaged or not. Can anyone point to a direct source, article, FAQ from AMD that specifically states their CPUs temperature range? Or are CPU temperature ranges so varying that there's no possible baseline? Am I being too paranoid about this? To me, anything over 65C is a bit much and if I'm in the low-mid 70s range with NO VMs running, what can I expect if I have several VMs running?

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  • Safe use of Update-FormatData?

    - by Steve B
    In a custom PowerShell module, I have at the top of my module definition this code: Update-FormatData -AppendPath (Join-Path $psscriptroot "*.ps1xml") This is working fine as all .ps1xml files are loaded. However, the module is sometimes loaded using Import-Module MyModule -Force (actually, this is in the install script of the module). In this case, the call to Update-FormatData fails with this error : Update-FormatData : There were errors in loading the format data file: Microsoft.PowerShell, c:\pathto\myfile.Types.ext.ps1xml : File skipped because it was already present from "Microsoft.PowerShell". At line:1 char:18 + Update-FormatData <<<< -AppendPath "c:\pathto\myfile.Types.ext.ps1xml" + CategoryInfo : InvalidOperation: (:) [Update-FormatData], RuntimeException + FullyQualifiedErrorId : FormatXmlUpateException,Microsoft.PowerShell.Commands.UpdateFormatDataCommand Is there a way to safely call this command? I know I can call Update-FormatData with no parameters, and it will update any known .ps1xml file, but this would work only if the file has already been loaded. Can I list somewhere the loaded format data files? Here is a bit of background: I'm building a custom module that is installed using a script. The install script looks like : [CmdletBinding(SupportsShouldProcess=$true,ConfirmImpact="High")] param() process { $target = Join-Path $PSHOME "Modules\MyModule" if ($pscmdlet.ShouldProcess("$target","Deploying MyModule module")) { if(!(Test-Path $target)) { new-Item -ItemType Directory -Path $target | Out-Null } get-ChildItem -Path (Split-Path ((Get-Variable MyInvocation -Scope 0).Value).MyCommand.Path) | copy-Item -Destination $target -Force Write-Host -ForegroundColorWhite @" The module has been installed. You can import it using : Import-Module MyModule Or you can add it in your profile ($profile) "@ Write-Warning "To refresh any open PowerShell session, you should run ""Import-Module MyModule -Force"" to reload the module" Import-Module MyModule -Force Write-Warning "This session has been refreshed." } } MyModule defines, as first statement, this line : Update-FormatData -AppendPath (Join-Path $psscriptroot "*.ps1xml") As I updated my $profile to always load this module, the Update-Path command has been called when I run the install script. In the install script, I force import the module, which be fire again the module, and then, the Update-Path call

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  • How to manage unprivileged administration of system services using Debian?

    - by ypnos
    At our lab, we have several services handled by different phd students (like myself). Fluctuation is high and people do the job next to their research duties. Until now, services were running on different machines, with different OS setups that can result in administration hell quickly. We want to consolidate our service setup. Our main idea is that the guys responsible for the services should not meddle with the underlying system anymore. Apart from core systems like NFS and kerberos, a typical service is able to run as non-root already. I'm talking about apache, mysql, subversion, mail with openxchange, and so on. Redirecting privileged ports is also no issue (source). What is left is the configuration of the service and its payload. One scenario we envisioned is that every service has its own user and home directory, accessable by the corresponding admins. Backup and fallback of the service is easy, as everything needed for the service to run is found in one place. Are there established ways to create such a setup? Does a mostly unique method exist to make services find their files (other than in system directories) while still using the corresponding debian packages? Are there any catches with our idea that we may have overlooked? Would you maybe claim that virtualization is the answer to our problem? (In our POV, it wouldn't help us keeping system setup strictly separated from service setup.) Thank you for any advice!

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  • Mysqld shutting down by itself

    - by AJ Naidas
    I'm running a Wordpress Blog that gets medium-high traffic. It is hosted in an Ubuntu Server 2GB Memory 2 Core Processor 40GB SSD Disk, 3TB Transfer. The problem is that MySQL shuts down by itself after an hour or two. I had to restart mysql each and every time this happens. I checked the logs and this is what I found: 140612 6:48:14 [Warning] Using unique option prefix myisam-recover instead of myisam-recover-options is deprecated and will be removed in a future release. Please use the full name instead. 140612 6:48:14 [Note] Plugin 'FEDERATED' is disabled. 140612 6:48:14 InnoDB: The InnoDB memory heap is disabled 140612 6:48:14 InnoDB: Mutexes and rw_locks use GCC atomic builtins 140612 6:48:14 InnoDB: Compressed tables use zlib 1.2.3.4 140612 6:48:14 InnoDB: Initializing buffer pool, size = 1.4G InnoDB: mmap(1502412800 bytes) failed; errno 12 140612 6:48:14 InnoDB: Completed initialization of buffer pool 140612 6:48:14 InnoDB: Fatal error: cannot allocate memory for the buffer pool 140612 6:48:14 [ERROR] Plugin 'InnoDB' init function returned error. 140612 6:48:14 [ERROR] Plugin 'InnoDB' registration as a STORAGE ENGINE failed. 140612 6:48:14 [ERROR] Unknown/unsupported storage engine: InnoDB 140612 6:48:14 [ERROR] Aborting 140612 6:48:14 [Note] /usr/sbin/mysqld: Shutdown complete judging by this line: 140612 6:48:14 InnoDB: Fatal error: cannot allocate memory for the buffer pool I suspect that this is a memory problem, but I would like to hear from the experts here before I conclude. Is this a lack of memory problem? Do you think the value of max_connections in my.cnf (currently 100) is a potential cause and needs increasing? TIA.

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  • How to verify TRIM/discard on encrypted swap?

    - by svarni
    I am using an encrypted swap partition via ecryptfs-setup-swap on my Ubuntu 13.04 computer using a SSD. I have manually set up trim for my ext4 root partition (simply by adding the "discard" option in /etc/fstab). I also manually ran fstrim on the root partition prior to booting and using dstat I saw that for a few seconds several GB/s of data have been written to the disk. That was presumably the effect of the trim command. These high writerates are reproducable by deleting huge files and have not occured before setting up trim, so I take them as evidence for working trim/discard. Manually enabling trim on my root partition has stopped the wearout of my precious new disk from 365 used reserved blocks (out of 6176 total) within three months down to 0 additional used reserved blocks within three additional months (data from SMART attributes). Because I want to minimize the wearout of my SSD I now would like to know whether my swap partition (which is encrypted using ecryptfs-setup-swap) also makes use of the trim/discard option. I tried sudo swapon -d -v /dev/mapper/cryptswap1 but did not receive particular information ("-v") about whether trim/discard ("-d") was applied. If unsupported, i would expect a message. Then I tried sudo dd if=/dev/sda6 count=1 BS=1M | xxd | less directly after booting and when no swapspace was used but I saw not only zeroes. I assume, when looking at freshly trimmed regions, the disk would send zeroes instead of reading random sectors (and according to some forums, (unencrypted) swap space is trimmed once upon boot). Long story short: Are there any ideas on how to test if trim is effectively used for my encrypted swap? And if not, any ideas on how to - at least manually, for once - trim the whole swap space? I wouldn't want to tinker with the partition itself, because I dont know if it needs to be reinitialized as (encrypted) swap - I dont want to be left with an unbootable system :)

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  • Network switches for LAN party

    - by guywhoneedsahand
    I am working on setting up the network for a small LAN party (less than 16 people). Most of them do not have wireless cards in their rigs, so I need to set up some way for everyone to a) play LAN games and b) access the internet. The LAN party will probably take place in my basement, where I have enough space. However, the basement is not wired up with the router which is actually on the floor above. I make a cantenna a while back that can boost the wireless performance of my computer significantly. How can I use this to provide internet and LAN to guests? My hope was that I could use a switch like this http://www.newegg.com/Product/Product.aspx?Item=N82E16833181166 for the LAN - but how can I give people access to the internet? Is there such thing as a network extender / 16-port switch? Obviously, the internet performance doesn't need to be super stellar, because the games will be using LAN - so I am looking to provide some usable internet for web browsing, and very high speed LAN for games. Thanks!

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  • xen + debian network after upgrade squeeze to wheeze

    - by rush
    I've got a Debian + Xen server. After a system upgrade to the stable version the network doesn't come up after boot. Every time after reboot I need to bring it up manually. The network configuration was not changed during upgrade. Here is /etc/network/interfaces: auto lo iface lo inet loopback auto eth0 iface eth0 inet static address 11.22.33.44 netmask 255.255.255.0 gateway 11.22.33.1 nameserver 8.8.8.8 After boot ip r shows no route and eth0 has no ip address. Manually ip and route setup goes fine and network starts working. Messages from dmesg about network I've found (looks like nothing interesting) [ 3.894401] ACPI: Fan [FAN3] (off) [ 3.894444] ACPI: Fan [FAN4] (off) [ 4.178348] e1000e 0000:00:19.0: eth0: (PCI Express:2.5GT/s:Width x1) 00:1e:67:14:66:c9 [ 4.178351] e1000e 0000:00:19.0: eth0: Intel(R) PRO/1000 Network Connection [ 4.178392] e1000e 0000:00:19.0: eth0: MAC: 10, PHY: 11, PBA No: 0100FF-0FF [ 4.178413] e1000e 0000:02:00.0: Disabling ASPM L0s L1 [ 4.178432] xen: registering gsi 16 triggering 0 polarity 1 -- [ 4.223667] ata5: DUMMY [ 4.223668] ata6: DUMMY [ 4.289153] e1000e 0000:02:00.0: eth1: (PCI Express:2.5GT/s:Width x1) 00:1e:67:14:66:c8 [ 4.289155] e1000e 0000:02:00.0: eth1: Intel(R) PRO/1000 Network Connection [ 4.289245] e1000e 0000:02:00.0: eth1: MAC: 3, PHY: 8, PBA No: 1000FF-0FF [ 4.506908] usb 1-1: new high-speed USB device number 2 using ehci_hcd [ 4.542920] ata2: SATA link up 3.0 Gbps (SStatus 123 SControl 300) -- [ 10.362999] EXT4-fs (dm-23): mounted filesystem with ordered data mode. Opts: (null) [ 10.419103] EXT4-fs (dm-3): mounted filesystem with ordered data mode. Opts: (null) [ 10.988255] ADDRCONF(NETDEV_UP): eth1: link is not ready [ 13.175533] Event-channel device installed. [ 13.287555] XENBUS: Unable to read cpu state -- [ 13.288670] XENBUS: Unable to read cpu state [ 13.965939] Bridge firewalling registered [ 14.134048] e1000e: eth1 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: Rx/Tx [ 14.283862] ADDRCONF(NETDEV_UP): peth0: link is not ready [ 14.284543] ADDRCONF(NETDEV_CHANGE): eth1: link becomes ready [ 17.800627] e1000e: peth0 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: Rx/Tx [ 17.801377] ADDRCONF(NETDEV_CHANGE): peth0: link becomes ready [ 18.307278] device peth0 entered promiscuous mode [ 24.538899] eth1: no IPv6 routers present [ 28.570902] peth0: no IPv6 routers present I've upgraded two servers and I've such behaviour on two of them. How to fix this and get network starts automatically on boot?

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  • using i7 "gamer" cpu in a HPC cluster

    - by user1219721
    I'm running WRF weather model. That's a ram intensive, highly parallel application. I need to build a HPC cluster for that. I use 10GB infiniband interconnect. WRF doesn't depends of core count, but on memory bandwidth. That's why a core i7 3820 or 3930K performs better than high-grade xeons E5-2600 or E7 Seems like universities uses xeon E5-2670 for WRF. It costs about $1500. Spec2006 fp_rates WRF bench shows $580 i7 3930K performs the same with 1600MHz RAM. What's interesting is that i7 can handle up to 2400MHz ram, doing a great performance increase for WRF. Then it really outperforms the xeon. Power comsumption is a bit higher, but still less than 20€ a year. Even including additional part I'll need (PSU, infiniband, case), the i7 way is still 700 €/cpu cheaper than Xeon. So, is it ok to use "gamer" hardware in a HPC cluster ? or should I do it pro with xeon ? (This is not a critical application. I can handle downtime. I think I don't need ECC?)

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  • Recommended Smartphone for Reading PDFs [closed]

    - by mika
    This is as much a software than a hardware question. I use a lot of public transport and perhaps the best way to spend your time there is to read while listening to music. Currently I use Nokia E90 and Adobe Reader LE 2.5 (full version). I was wondering if there are any better alternatives? Requirements: at least 640px wide screen, preferably 800px physical size of the LCD display matters, it should be large, but the phone itself should be as small as possible. This favors touchscreen models PDF reader should be of high quality. It should render most PDFs correctly. Other important features include: full screen mode, keyboard controls for Page Down and page change, multiple zoom levels to adjust to the screen, opening recent documents at the last page read Downsides of E90 + Adobe Reader LE Phone is large compared to the display It is hard to read the display at sunlight Adobe Reader crashes the phone regularly, zoom could have more levels, doesn't remember last page EDIT: Switched to iPhone and GoodReader. Smaller physical screen width compared to E90 is a disimprovement, but other than that I'm happy. GoodReader is the highest quality smartphone PDF reader I've seen so far.

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  • Setting up a global MySQL Cluster in the cloud

    - by GregB
    I'm giving the question an overhaul to more specifically identify where I need help. I use two tools to manage a bunch of cloud server: Puppet and Rundeck. Both of these can be configured to use a mysql backend. I'd like to setup an instance of each application in both the U.S., and the U.K., treating the U.K. servers as hot stand-bys in case of failure in the U.S. I want to use a MySql cluster so that the data is automatically replicated from the U.S. to the U.K. Because these are hot standbys, high performance is not a goal. Redundancy and data integrity are most important. My question revolves around the setup of the mysql cluster. I want to run three servers, each one running a data node, a sql node, and a management node. Is this a valid configuration for mysql server? If so, could someone point me in the right direction for creating such a setup? I've downloaded the offical tarball, and the official debian, and the documentation for them contradicts many of the online tutorials. I'm installing on Ubuntu 10.04.

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  • EC2 Auto-Scaling with Spot and On-Demand Instances?

    - by platforms
    I'm looking to optimize the cost of our auto-scaling EC2 groups by having them launch spot instances instead of on-demand instances. What I really want is to be able to keep some servers in the group as on-demand instances, regardless of what happens to the spot instance pricing market. Then I want any additional servers in the group, above my configured minimum, to be spot instances. I'm generally OK with the delay in adding servers via spot requests. I can't seem to find any way to do this and I've tried to scour the AWS documentation. It appears that an ASG can either be on-demand or spot, but not a hybrid. I could possibly manually add an on-demand instance to the Elastic Load Balancer assigned to the auto-scaling group, but then the load of that server would not be factored into the auto-scaling measurements and triggers. I suppose I could enter a ridiculously high bid price in order to ensure that I always get the servers I need, but then I look at the pricing history and see occasional large spikes. The AWS documentation is at odds with itself, since in one place it says that if you enter a server minimum, that number is "ensured" to be there. But then when you read about spot instances, there are no assurances. The price differential for spot is compelling, so I'd like to leverage that as much as I can while still maintaining an always-on baseline. Is this possible?

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  • Start Chrome by command line, but adding some arguments to make it login into your Google account automatically

    - by jim
    Is there a way to start Chrome calling it from the command line (using Linux), but providing it some argument to make it login into some Google account automatically? I'm looking for something like google-chrome -account foo -pass bar that I can easily put in a bash script later. A little background: I have a laptop connected to my TV, which is currently using just a mouse for user interaction. There's no google account logged in by default, and that's the way I want to keep it, so my kids can't come across videos and pictures in google and youtube that they are not supposed to see (e.g.: adult content, or anything marked as not appropriate for kids by the google's safe search filters). The bad thing about this is that there are some music videos in youtube that requires you to be logged in to see, usually those we (the adults) used to sing when playing karaoke... as the only input available is a mouse, I'm looking for a way to start with my google account without having to type the whole thing usin the on-screen keyboard. You may think "Why you can't use the keyboard, if the laptop is right there?". Well, it's in a kind of uncomfortable position - too high for me without a chair or something, as it's right above the furniture in where the TV is located. Is there a way to make this scriptable? If not, do you know any other workaround? Note: using the remember me after logging off or alike options are discarded, as the safe-search chrome version must be always the default version to run.

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  • How to set an executable white list?

    - by izabera
    Under Linux, is it possible to set a white-list of executables for a certain group of users? I need them to be unable to use, for example, make, gcc and executables on removable disks. How can this be done? Edit, let me explain better. I'm dealing with a high school IT system, young geeks that (during the lessons) want to play, surf the net, damage those computer however they can. The major step to achieve this goal was to remove the system they're familiar with and install Ubuntu in all the computers. This actually works quite well, but recent events proved that this is not enough. I want to allow them to execute certain safe programs, like Open Office, and to deny any other program, whether it is preinstalled software, something they carry in usb drives, a downloaded program or a script they program on site. It's possible to remove the 'x' permission on any file on the pc, but of course it would be impractical. Furthermore, they would be able to run anything they download. I thought the best solution would be to make a white-list of safe programs and to deny anything else, but I don't really know how to do it. Any idea is helpful.

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  • Disk Activity Alert Windows SBS 2003 on Dell PowerEdge 830 with Raid

    - by Ron Whites
    Background: I have a Dell PowerEdge 830 Server running Windows SB Server 2003. It has 4gbs of RAM and a ATA CERC SATA 6CH controller with 3 160gb drives in a Raid 5 configuration. The Problem I am seeing Admin ---"Disk Activity Alert on Server" emails These often occur when disk backups, de-frag or high disk usage is going on. Generally the server isn't over stressed. The Disk Alert emails say in part ... The following disk has low idle time, which may cause slow response time when reading or writing files to the disk. Disk: 0 C: F: D: Review the Disk Transfers/sec and % Idle Time counters for the PhysicalDisk performance object. If the Disk Transfers/sec counter is consistently below 150 while the % Idle Time counter remains very low (close to 0), there may be a problem with the disk driver or hardware. The Questions I have: With what utility can I review the Disk Transfers/sec and Idle Time? It appears there is no utility for that on the server! I think I may need to download a very large (two DVD) Dell "OpenManage" utility to be able to monitor the raid system and see what is a problem is that true?

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  • Hearing a clicking noise from soundcard all the time

    - by Mehrdad
    I have installed Fedora 17 on my laptop. A few days ago I updated my fedora (but not upgraded). I shut down my computer and since the next time I turned it on I am hearing a clicking noise all the time from speakers. Even when I plug my headphones in I hear the noise through the headphone. I surfed over the internet and found the following shell commands: su -c 'echo "options snd_hda_intel power_save=0" /etc/modprobe.d/snd_hda_intel.conf' su -c 'echo 0 /sys/module/snd_hda_intel/parameters/power_save' I tried them but they didn't work. Here is the part of "lspci" command related to my sound-card: 00:1b.0 Audio device: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) High Definition Audio Controller (rev 03) I have to add that my sound-card is working and I can play some audio file, I mean I can hear the voice and noise simultaneously. But everything is OK in windows xp which is also installed on my laptop. Could it be related to the sound-card driver? If so, how can I revert it to the previous version?

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