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Kernel update for Centos 4
by mbneto 14 Feb '08

14 Feb '08

Hi, I've noticed that we already have an updated kernel for the Centos 5. Any idea of when the same thing will happen for Centos 4 386 ? Thanks.

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Strange performance issues under CentOS 5.1
by Alfred von Campe 14 Feb '08

14 Feb '08

I am still running CentOS 4.6 on our production systems, but I am starting to plan the upgrade to CentOS 5.1. I have one test system running 5.1 that is the exact same hardware configuration as my 4.6 test system. One of our builds runs about 6 times slower on the 5.1 system, even though is uses less overall CPU time. I first suspected something wrong with the disk, but the results from bonnie++ show that the 5.1 system is slightly faster: Version 1.03 ------Sequential Output------ --Sequential Input- --Random- -Per Chr- --Block-- -Rewrite- -Per Chr- -- Block-- --Seeks-- Machine Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec % CP /sec %CP centos4.6 16G 35933 10 21301 5 46507 6 41.8 0 Version 1.03 ------Sequential Output------ --Sequential Input- --Random- -Per Chr- --Block-- -Rewrite- -Per Chr- -- Block-- --Seeks-- Machine Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec % CP /sec %CP centos5.1 16G 42015 14 21179 5 49863 4 91.6 0 Then I ran the build with "/usr/bin/time --verbose", and here are the results (first 4.6 then 5.1): Command being timed: "make" User time (seconds): 32.15 System time (seconds): 3.52 Percent of CPU this job got: 99% Elapsed (wall clock) time (h:mm:ss or m:ss): 0:35.88 Command being timed: "make" User time (seconds): 22.05 System time (seconds): 3.11 Percent of CPU this job got: 11% Elapsed (wall clock) time (h:mm:ss or m:ss): 3:31.35 As you can see from the above, there is a lot of idle time on the 5.1 system. Finally, I ran the build with "strace -c", and here are the top ten lines of that output (again, 4.6 first and then 5.1): % time seconds usecs/call calls errors syscall ------ ----------- ----------- --------- --------- ---------------- 53.81 16.804147 54916 306 58 waitpid 34.75 10.853461 82851 131 wait4 5.29 1.650844 9 177706 154581 open 1.61 0.503701 15 34408 read 0.91 0.283706 15 18607 write 0.60 0.185894 12 14919 10364 stat64 0.52 0.163340 10 16495 9079 access 0.47 0.146933 7 20581 mmap2 % time seconds usecs/call calls errors syscall ------ ----------- ----------- --------- --------- ---------------- 60.07 15.173924 52687 288 58 waitpid 38.50 9.724412 83831 116 wait4 0.54 0.135194 7 19199 10705 access 0.36 0.090850 54 1681 1334 execve 0.27 0.067686 5 14423 10570 stat64 0.11 0.027676 1 24832 read 0.09 0.022339 0 155810 135765 open 0.03 0.007617 159 48 unlink Any suggestions as to what could possible be causing this? I am fresh out of other ideas to try. Alfred

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RE: [Iscsitarget-devel] Performance Question
by Joseph L. Casale 14 Feb '08

14 Feb '08

>Yes, jumbo frames, no irq coalescence, blockio and see if >you can get Backup Exec to use large io request sizes when >reading and writing the data. The larger the better. Ok, Jumbo's enabled on the switch and media server. For the sake of our sanity jumping back and forth, I am trying to enable jumbo's on the bonded pair in the target, # ifconfig bond0 mtu 9014 and it errors out? Any idea what I am doing wrong? Also, where do I tune irq coalescence? Thanks! jlc

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RE: [CentOS] Apache RPM's
by Les Bell 13 Feb '08

13 Feb '08

"Ross S. W. Walker" <rwalker(a)medallion.com> wrote: >> I agree whole heartily. It would go a long way though if Redhat provided independent certification of their products under these compliance banners. << RHEL 5 is Common Criteria certified against the Controlled Access Protection Profile (CAPP), Labelled Security Protection Profile (LSPP) and Role-Based Access Control Protection Profile (RBACPP) at EAL (Evaluation Assurance Level) 4+ (i.e. all requirements of EAL4 and some of EAL5), when running on certain hardware platforms (IBM). See http://www.commoncriteriaportal.org/public/consumer/index.php?menu=5 for the reports. That may be overkill for what you require, but if your system is certified and accredited, it usually stops auditors in their tracks. I agree with concerns about the inability of auditors to correctly interpret requirements. The Y2K panic provided lots of examples; I recall one junior auditor demanding that a network hub be replaced because it was not "certified Y2K compliant". Best, --- Les Bell, RHCE, CISSP [http://www.lesbell.com.au] Tel: +61 2 9451 1144 FreeWorldDialup: 800909

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Re: [CentOS] pvmove speed
by Ross S. W. Walker 13 Feb '08

13 Feb '08

Good suggestion, no it's not ESX, but it does do snapshots. -Ross ----- Original Message ----- From: centos-bounces(a)centos.org <centos-bounces(a)centos.org> To: 'CentOS mailing list' <centos(a)centos.org> Sent: Wed Feb 13 17:30:39 2008 Subject: RE: [CentOS] pvmove speed >I am facing the same issue with a migration of our VM machines >to a new iSCSI setup this year, around 1TB of VMs need to be >fork lifted over and I thought about exotic ways to move it >over, but I think in the end it will be by good ole backup exec >and tape. You're not running esx are you? Heh, I just did the same thing on a much smaller scale. Couldn't afford the long downtime while a copy took place so I shut the vm's off, snapped it and restarted it. I then scripted all files "without" 00000 in the name to rsync over (ssssslowly). I then only had to shut the vm off and sync the small snap's and restart the vm's on other storage. Only took a few minutes. jlc _______________________________________________ CentOS mailing list CentOS(a)centos.org http://lists.centos.org/mailman/listinfo/centos ______________________________________________________________________ This e-mail, and any attachments thereto, is intended only for use by the addressee(s) named herein and may contain legally privileged and/or confidential information. If you are not the intended recipient of this e-mail, you are hereby notified that any dissemination, distribution or copying of this e-mail, and any attachments thereto, is strictly prohibited. If you have received this e-mail in error, please immediately notify the sender and permanently delete the original and any copy or printout thereof.

1 0

upgrade from Fedora Core 5
by Peter Horst 13 Feb '08

13 Feb '08

Hi - It was recommended to me on the Fedora list that I consider upgrading to CentOS 5 from my present FC5 - the machine is used only as a light-duty CLI-only server. I have a couple of quick questions in that regard: 1. Is now a bad time to install CentOS 5, what with the root exploit out and about? Should I wait for a new kernel? 2. I just picked up a Cavalry 1TB external USB HD, the CADB001U32, which I want to use for backup purposes. I formatted it with one ext3 partition. If I load all my data onto that drive, then upgrade my main machine to CentOS 5 (which I assume will involve a complete wipe), should I then be able to mount it and retrieve the data? Thank you very much.

2 2

pvmove speed
by Joseph L. Casale 13 Feb '08

13 Feb '08

Are there any ways to improve/manage the speed of pvmove? Man doesn't show any documented switches for priority scheduling. Iostat shows the system way underutilized even though the lv whose pe's are being migrated is continuously being written (slowly) to. Thanks! jlc

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fsck
by Centos 13 Feb '08

13 Feb '08

Hello our server is crashed and now some files are missing. when I do ls, I can see the file but when I do ls -la, file does not show up. I am going to do fsck, but was wondering if there is any other quick fix rather than umount and do fsck. Thanks

2 1

Backport uncertainty
by Joseph L. Casale 13 Feb '08

13 Feb '08

I need to know of my version of Postfix supports a feature, given rh version numbers don't really tell you much I was trying to find an errata on postfix or anything to let me know the real version of it. How does one deal with this scenario? Is there a source of info to determine this info? Thanks! jlc

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How can I stop the eject of the DVD after install?
by Lundgren, Andrew 13 Feb '08

13 Feb '08

I have created my own install DVD with a custom kickstart file and modified the isolinux.cfg file to allow the system to boot off of the hard disk as the default mode. It will also use my kickstart file if I select it. Now I would like to make the system not eject the DVD after reboot. The machines I am installing on do not have a motorized tray that can automatically pull the DVD back in when a mount command is issued. You have to push the disk in manually. As these machines will be unattended that is not idea. How can I prevent the installer from ejecting the DVD once the install is complete? Thanks! -- Andrew Lundgren

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