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my notes on bond, bridge, network, kvm, host and virtual so far
by Bob Hoffman 14 Feb '12

14 Feb '12

I put this page together just so I won't spam the board anymore begging for help..lol http://bobhoffman.com/vmissue.html This shows a working effort of bonded eths, bridged into a vm, and a few other things. The only missing thing is something on the host that ends up putting the VM internet connection into some kind of limbo. Whether it is hardware related, bug related, libvirt nat related, I don't know. I will only post here on this issue again if it ever gets solved. At this point the server is a no go and getting shelved until I can find a tech that knows this stuff and can fix it. right now: unsolvable. I may just put some websites on the host computer until I can find a reliable way of keeping the virtual guest connection 100% up. Hope this helps someone wanting to bridge or bond. bob

6 11

MySQL/file system question
by Boris Epstein 14 Feb '12

14 Feb '12

Hello listmates, I got a rather strange situation that I can't quite make sense of. OK, I've got a very large data file to sort (hundreds of millions of lines) and I decided to use MySQL for the purpose. I inserted the stuff into a table easily enough. Then I decided to sort it and got stuck as it turned out that MySQL, unless specifically configured to do otherwise, puts temporary files in /tmp which simply was not sufficiently large. Then I changed that directory to a partition that had more space (let's call the new temp driectory /home/big-temp) and now as I am running the query aimed at sorting the data it seems like space, according to the df, is no longer being used up under / (which was there /tmp was) but is now being used up in the right partition ( /home, the large one). Yet /home/big-temp is still empty! So how is that possible? I know there are all kinds of file locking possible depending on the circumstances, file system type, etc - but how can it be that the files, if they exist, are not even visible to ls, even "ls -a", even run by root? Thanks in advance for any clarification. Cheers, Boris.

4 9

oops, or how to bring a datacenter router down with one setting
by Bob Hoffman 14 Feb '12

14 Feb '12

so I gave up on bonding. I found about 300 posts showing eth0 and eth1 both pointing to br0 (bridge) as interfaces. I followed them correctly, or so I thought. I pointed both ethx to the bridge, restarted network and bam...!!! entire ip block went out. when I called datacenter they told me the router was under attack and I was like 'uh oh' and told them to just shut off my computer I would be there to fix it. They did not believe me. An hour later I was there and deleted the eth1 point to the br0 and all was fine. Meanwhile they were all around the router trying to stop the attack. (it was just the router for me and others in that room....oops) I wonder if they will boot me from the center now? How is it possible that it did that so quickly? Such an easy way to bring down routers, wow, a hacker could have a field day. Apparently there is more to making to eth ports go to the same bridge than a simple point. I have since tried bridge_ports command as listed online, however that must be deprecated. I think I am just gonna stay with multiple bridges with one eth on each for a while until I can test this stuff in a safe environ. I never had a chance to recover, the second the network came up I lost all contact with my ip block. The ratelimit number got this high by the time I got there. Feb 9 04:22:41 main kernel: __ratelimit: 100807 callbacks suppressed Feb 9 04:22:41 main kernel: eth1: received packet with own address as source address Feb 9 04:22:41 main kernel: eth1: received packet with own address as source address Feb 9 04:22:41 main kernel: eth1: received packet with own address as source address Feb 9 04:22:41 main kernel: eth1: received packet with own address as source address Feb 9 04:22:41 main kernel: eth0: received packet with own address as source address Feb 9 04:22:41 main kernel: eth0: received packet with own address as source address Feb 9 04:22:41 main kernel: eth0: received packet with own address as source address Feb 9 04:22:41 main kernel: eth0: received packet with own address as source address Feb 9 04:22:41 main kernel: eth0: received packet with own address as source address Feb 9 04:22:41 main kernel: eth0: received packet with own address as source address

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Removing All Packages From Repository
by Matt 13 Feb '12

13 Feb '12

Is there a way to remove all packages from a certain repository such as RPMFORGE?

4 3

displaying user and group names in chroot sftp
by James B. Byrne 13 Feb '12

13 Feb '12

I am testing a chrooted environment for sftp using the internal-sftp subsystem. Now that I seem to have SELinux mostly out of the way, when I do an 'ls -l' after the sftp login I see only numbers for the uids and gids. When I was using scponly I simply had a local version of /etc/passwd and /etc/group but these are evidently not used by the internal sftp subsystem. Is there a way to get the internal sftp subsystem to deliver names instead of the numbers? -- *** E-Mail is NOT a SECURE channel *** James B. Byrne mailto:ByrneJB@Harte-Lyne.ca Harte & Lyne Limited http://www.harte-lyne.ca 9 Brockley Drive vox: +1 905 561 1241 Hamilton, Ontario fax: +1 905 561 0757 Canada L8E 3C3

1 0

Anyone already tried to backport the latest ASPM kernel patch to 6.2?
by Michael Lampe 13 Feb '12

13 Feb '12

After going from CentOS 5.7 to 6.2, a lot of things turned out to be much better, but there are also quite some regressions. The most obvious one is power consumption on my notebook. It was notably lower before. The ASPM issue introduced in 2.6.38 was widely reported and discussed, and the 6.2 kernel has exacatly this code as a backport. http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdi… So I started to experiment with the upstream patch: http://git.kernel.org/?p=linux/kernel/git/stable/linux-stable.git;a=commitd… To make it apply, one needs to change 'pci_is_pcie(pdev)' into 'pdev->is_pcie'. One also needs to fiddle a little with the first chunk. I came up with the patch attached, but unfortunately the new kernel showed no improvement. Most probably I got something wrong. Anyone else here who tried this or is interested in sorting this out? Thanks, Michael

3 6

Adding Mandarin support - pointers?
by m.roth＠5-cent.us 13 Feb '12

13 Feb '12

I've had a request from one of my users to add Mandarin support. A few quick googles gets me nothing, nor looking for "adding language support". Anyone have a pointer to info on adding whatever packages/group packages I need? Thanks in advance. mark

4 4

Perl Libraries
by Matt 12 Feb '12

12 Feb '12

Having troubles with perl libraries. Does everyone use yum to install perl modules on CentOS 5.x? I have installed the rpmforge repository. I am having terrible luck with installing libraries though. Needed Mechanize for one script but had all sorts of conflicts. Ended up installing mechanize manually from rpm and adding it to yum exclude. Right now I am trying to get Net::SSH::Perl installed and run this script: http://www.perlhowto.com/execute_commands_on_remote_machines_using_ssh Would think it would be as simple as 'yum install perl-Net-OpenSSH' but it does not work. It installs but perl complains when using it. Is it better to use CPAN instead of yum? For those doing a good deal of perl scripting what are you using to manage libraries? Any pointers would be great.

5 10

Can I get rid of i86 packages and libraries on an x86_64 virtual server?
by John J. Boyer 12 Feb '12

12 Feb '12

The server is a vpn with only 20 GB of storage. I would like to free up disk space. Even if I must keep some i86 stuff, I think I can get rid of the dev packages for it. Thanks, John -- John J. Boyer; President, Chief Software Developer Abilitiessoft, Inc. http://www.abilitiessoft.com Madison, Wisconsin USA Developing software for people with disabilities

3 2

Key auth question
by Jussi Hirvi 12 Feb '12

12 Feb '12

I have a problem getting key authentication to work with one remote user (git), even though it works fine for the remote user "root". The remote file .ssh/authorized_keys is identical for both users - I cp'ed it from the root account to the git home dir. On local machine (OS X, by the way) I have: $ cd $ ls -l .ssh -rw------- 1 jussihirvi staff 668 Aug 24 16:13 id_rsa (the rest is omitted) On remote machine (as root): $ cd $ ls -ld .ssh drwxr-xr-x 2 root root 4096 Feb 11 17:45 .ssh $ ls -l .ssh total 8 -rw------- 1 root root 1768 Feb 11 17:45 authorized_keys -rw-r--r-- 1 root root 631 Feb 11 12:30 known_hosts On remote machine (as git): $ cd $ ls -ld .ssh drwxr-xr-x 2 git git 4096 Feb 12 11:15 .ssh $ ls -l .ssh total 8 -rw------- 1 git git 1768 Feb 12 10:52 authorized_keys -rw-r--r-- 1 git git 631 Feb 12 11:05 known_hosts When, on local machine, I do: $ ssh root@remotehost I get in without a password. But when I do $ ssh git@remotehost I will be asked for a password. What should I check? - Jussi -- Jussi Hirvi * Green Spot Suvilahdenkatu 1 B 78 * 00500 Helsinki * Finland Tel. +358 9 493 981 * Mobile +358 40 771 2098 (only sms) jussi.hirvi(a)greenspot.fi * http://www.greenspot.fi

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