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[Slightly OT] Data Preservation
by ML 05 Oct '09

05 Oct '09

HI All, So I have 5 1U servers (running Windows) that have Ultra 320 SCSI Drives in them. The owner of these boxes wants the drives captured in their current states to .iso or .cdr or something where if the need arises the data can be viewed, used again, etc. So what is the best approach? Boot from a Live CD, hook up a USB external HD and do what? Can I create a .iso or .cdr (or some other portable format) and have it created on the external USB? Thoughts on this process would be appreciated. -ML

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Can't get forwarding to work
by Neil Aggarwal 05 Oct '09

05 Oct '09

Hello all: I am having trouble getting port forwarding with iptables to work. I have this configuration: Internet --- Linux machine --- Windows machine The windows machine is set up to listen on IP address 10.0.0.31 I am able to use lynx to connect to http://10.0.0.31 on the linux machine so there is no problem going from the linux machine to the windows machine. I have tied a public IP address a.b.c.d to the linux machine and entered these rules in its firewall: /sbin/ifconfig eth0:1 $WIN_EXTERNAL_IP netmask $ETH0_NETMASK broadcast $ETH0_BCAST /sbin/iptables -t nat -A PREROUTING -p tcp -i eth0 -d $WIN_EXTERNAL_IP --dport 80 -j DNAT --to $WIN_INTERNAL_IP:80 /sbin/iptables -A FORWARD -p tcp -i eth0 -d $WIN_INTERNAL_IP --dport 80 -j ACCEPT I have this log entry at the bottom of the firewall rules: /sbin/iptables -A FORWARD -j LOG --log-prefix "FORWARD " When I try to go to the external IP address http://a.b.c.d from another network, I get an error. Any ideas? Thanks, Neil -- Neil Aggarwal, (281)846-8957, www.JAMMConsulting.com Will your e-commerce site go offline if you have a DB server failure, fiber cut, flood, fire, or other disaster? If so, ask about our geographically redundant database system.

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problem with installing centos 5.3 on sata ahci
by Maciej Jan Broniarz 04 Oct '09

04 Oct '09

Hello, I am trying to install Centos on sata ahci. The installer first waits few minutes while loading ahci module. Then, the installer cannot detect any disk during the partitioning phase. What might be the problem? I have switched to IDE in bios and it still is the same. Best regards, mjb

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Testing and using a microphone
by Niki Kovacs 04 Oct '09

04 Oct '09

Hi, What's the most simple way to check if my microphone works on a plain CentOS 5.3 desktop? Is there a simple way, for example, to record voice into a simple .wav file? Niki

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NFS lockups
by Mike Yates 04 Oct '09

04 Oct '09

I thought this had been fixed with newer kernels? We have an old Maxtor Snap Server, an 80 GB NAS unit, containing some of our archives. Both of our CentOS servers have it permanently mounted by NFS for convenient access. This weekend, I discovered remotely that, although all systems except the VRTSralus remote agents for Veritas (now Symantec) Backup Exec were working just fine, both servers would freeze a shell solid on starting to run "lsof" or half way through a "df". However, "mount" ran OK and showed the next item in the "df" should have been the Snap Server NFS mount. I pinged it and it did not respond - I'll let you know Monday what is up. "umount -f" showed "Device busy" but "umount -l" worked just fine and "df" "lsof" and "VRTSralus" all work OK now. BTW the Veritas does not access the Snap Server, though the weekly cron-job to tar-ball the Snap Server at 02:00 Saturday did not email me at all, though it is shown in /var/log/cron. Does anyone know of a method to make NFS mounts auto un-mount if the remote server disappears? Mike Yates MBCS CITP (ISSG) IT Support Engineer Hawkgrove Ltd - Software Systems Design 2, The Business Courtyard, Marl Pits Lane, Trudoxhill, Frome, Somerset, BA11 5DL, UK +44 (0)1373 837900 fax: +44 (0)8700 518155 Registered in England: 2756481 VAT Reg: UK 601 1137 11 Registered Office: NSO Associates LLP, 75 Springfield Road, Chelmsford, Essex CM2 6JB All e-mail is subject to contract and is not intended to create a legally binding agreement. Hawkgrove Ltd will only be bound by an agreement in writing signed by an authorized signatory. All outgoing email is scanned by Kerio, using ClamAV 0.94.2/9865/Sat Oct 3 03:45:19 2009 Known viruses: 625330.

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Monitoring OpenVPN TUNs with MRTG
by Eduardo Grosclaude 04 Oct '09

04 Oct '09

I want to check some client OpenVPN TUN interfaces with MRTG running at my VPN server, so I have to specify their OID interface numbers in mrtg.cfg. The problem is, these numbers are dynamic, as they may change whenever OpenVPN restarts for any reason... so, how can I write stanzas such as Target[somehostvpninterface] : ifInOctets.X&ifOutOctets.X:public@ <SOMEHOST.IP> without wiring up the X interface number into cfg file? Or, is there any method to keep X from changing at the clients? Any hints appreciated! -- Eduardo Grosclaude Universidad Nacional del Comahue Neuquen, Argentina

2 1

[Slightly OT] Data Preservation - More
by ML 03 Oct '09

03 Oct '09

Hi All, As it turns out these boxes are Red Hat Enterprise Linux and not Windows!. I am not sure how the person who asked me to do the work does not know what he had! I guess he was the CEO though! So I think this process becomes simpler. I should just be able to insert the live cd and do a cp -r on / to the destination USB drive, correct? -ML

5 11

Excessive NFS operations
by lhecking＠users.sourceforge.net 03 Oct '09

03 Oct '09

Reading the "waiting IOs" thread made me remember I have a similar problem that has been here for months, and I have no sulution yet. A single CentOS 5.2 x86_64 machine here is overloading our NetApp filer with excessive NFS getattr, lookup and access operations. The weird thing is that the number of these operations increases over time. I have an mrtg graph (which I didn't want to attach here) showing e.g. 200 NFS Ops on Monday, measured with filer-mrtg, going up to, e.g. 1200 in a straight line within days. nfsstat -l on the filer proves beyond doubt that the load is caused by this particular machine. dstat shows me which NFS operations are causing it. date/time | null gatr satr look aces ... 10-09 12:22:52| 0 0 0 0 0 10-09 12:22:53| 0 525 0 602 602 10-09 12:22:54| 0 1275 0 1464 1438 10-09 12:22:55| 0 0 0 0 0 10-09 12:22:56| 0 0 0 0 0 10-09 12:22:57| 0 0 0 0 0 10-09 12:22:58| 0 238 0 270 270 10-09 12:22:59| 0 1461 0 1663 1660 10-09 12:23:00| 0 205 0 133 114 10-09 12:23:01| 0 0 0 0 0 10-09 12:23:02| 0 1 0 0 0 10-09 12:23:03| 0 0 0 0 0 10-09 12:23:04| 0 1411 0 1574 1574 10-09 12:23:05| 0 498 0 465 466 10-09 12:23:06| 0 0 0 0 0 10-09 12:23:07| 0 0 0 0 0 10-09 12:23:08| 0 0 0 0 0 10-09 12:23:09| 0 1082 0 1178 1192 10-09 12:23:10| 0 790 0 885 865 This behaviour is somehow tied to the Gnome desktop. I have other machines running CentOS 5.2 x86_64 (at init level 3) which don't show this behaviour. I also have CentOS 5.2 i386 machines which don't show it either. None of the other machines on the lan show it - RHEL3 32 and 64bit, Solaris. What I'd need is a monitoring tool than can tie the NFS ops to process ids or applications. lsof isn't nearly as helpful here as I thought. I even copied this workstation user's files to another account, logged in and ran the same apps - and couldn't reproduce it. Ideas? Essentially, this makes CentOS 64bit undeployable in our environemnt.

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du vs df size difference
by Ryan Pugatch 02 Oct '09

02 Oct '09

Hi all, Curious issue.. looking in to how much disk space is being used on a machine (CentOS 5.3). When I compare the output of du vs df, I am seeing a 12GB difference with du saying 8G used and df saying 20G used. # du -hcx / 8.0G total # df -h / Filesystem Size Used Avail Use% Mounted on /dev/xvda3 22G 20G 637M 97% / I recognize that in most cases du and df are not going to report the same but I am concerned about having a 12GB disparity. Does anyone have any thoughts about this or reason as to why there is a big difference? I have read a few articles online about it and none have really shown such a large difference. Thanks Ryan Pugatch Systems Administrator, TripAdvisor

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Re: [CentOS] Asterisk and VOIP was Re: CentOS for non-tech user
by rb4centos＠gmail.com 02 Oct '09

02 Oct '09

-----Original Message----- From: Brian Mathis The difference is that CentOS is a general-purpose OS that can be used for many things, and has a much bigger installed base. That makes it more of a target and would likely be included in scanning tools. A custom OS running on a PBX might also have vulnerabilities, but it's also probably not a big target because of the diversity of systems out there and relative limited utility one would have if such a system were compromised. That you tend to tend to think of it as an "appliance" running the phone system does not change the fact that it's actually a full-blown server OS with the same issues as other servers. But if you're not connected to the Internet none of of this means anything. CentOS/Asterisk *would* be an appliance under these conditions. There are no "server" vulnerabilities because you're not connected to a LAN. Apologies if this is unreadable. I'm typing on my Centro and I do that very often.

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