Discuss September 2007

discuss@lists.centos.org

265 participants
310 discussions

[Semi-OT] Advice on large webmail setup
by Neil Thompson 03 Jan '08

03 Jan '08

Hi all, As the resident Linux guru, I've just been tasked with costing a webmail setup for about 600 000 users. They each have 10MiB (small, I know) mailboxes. The current setup has about 40 million web page accesses per month. Has anyone here any experience with this kind of thing? If so, any pointers as to software and hardware used, and any other advice would be appreciated. TIA -- Cheers! (Relax...have a homebrew) Neil THEOREM: VI is perfect. PROOF: VI in roman numerals is 6. The natural numbers < 6 which divide 6 are 1, 2, and 3. 1+2+3 = 6. So 6 is a perfect number. Therefore, VI is perfect. QED -- Arthur Tateishi

14 21

Team CentOS breaks though the 200 ranking barrier.
by Sharon Kimble 23 Nov '07

23 Nov '07

Congratulations to all the CentOS folding@home team members for breaking through the 200 world ranking barrier. Its taken a bit of time but we've all helped to do it. Our next target is obviously to achieve 150th in the world ranking. But, to help achieve that we're going to need more members and more machines. So, if you think it sounds interesting and you want to learn more, then please have a look at http://www.sharons.org.uk/cf.html or ask in #centos-social on irc, or in the usual mailing list. Theres always someone on hand to advise or to point you in the direction of someone who could possibly help. Thanks everybody, and full steam ahead to the next target! :) Sharon. -- 14:20:05 up 9 days, 21:44, 2 users, load average: 2.89, 1.72, 1.62 A taste of linux http://www.sharons.org.uk/taste/index.html efever http://www.efever.blogspot.com/ Centos 4.4, KDE 3.5.4-6.0, OpenOffice 2.0.3 Registered Linux user 334501 Get my public GnuPG key from http://keyserver.veridis.com:11371/export?id=6499064243027013735

2 1

Announcement Project based on CentOS 4.4
by Tronn Wærdahl 29 Oct '07

29 Oct '07

I put together a CD with Open-exchange 0.8.6-5 and more, based on Centos 4.4 When installing the CD, all required software is installed, all that is needed after Os install is to run a config script, that make if fit your enviroment Dependig on the speed on your CDrom the installation should take no more than 30 minutts It install the following: - Open-Exchange 0.8.6-5 - Samba PDC - A PDF printer - Wildfire, a jabber server (for chating ) - Avaadm - Jetti, (jabber webclient) - Squid - Nameserver ( needed when join machins to domain) - Smartsive and websive - Antivirus - Syncml ( but i havent got it to work with any of my clients ) Since it could be so difficult to install, I put this together CD, and I guess allso others would have some use for it Its aviliable for download here http://ntx.waerdahl.net Tronn

9 21

Squid Parent: child process XXXX exited due to signal 25
by Mark Quitoriano 16 Oct '07

16 Oct '07

how do i prevent the logfiles from getting 2GB of file. what should i set in logrotate? thanks!

4 5

apt package in centos 4.5
by Mark Quitoriano 16 Oct '07

16 Oct '07

im having a problem with apt in centos 4.5 i get this error. # rpm -Uvh apt-0.5.15cnc6-4.centos4.i386.rpm warning: apt-0.5.15cnc6-4.centos4.i386.rpm: V3 DSA signature: NOKEY, key ID 443e1821 Preparing... ########################################### [100%] file /etc/apt/sources.list.d/centos.list from install of apt-0.5.15cnc6-4.centos4 conflicts with file from package centos-release-4-4.3 #

2 2

CentOS 5 IA64
by James A. Peltier 15 Oct '07

15 Oct '07

I only have this machine until Monday. I understand that there is a beta version around somewhere? Perhaps a developer can create an ISO that I can try to boot onto this machine?

3 2

pam_ldap + nscd
by Felix Schwarz 09 Oct '07

09 Oct '07

Hi, I'd like to use nscd for passwd+group caching. pam_ldap is configured and works (e.g. 'id foo' returns the correct user id if foo is present in ldap). If I start nscd manually (not started by default), 'id foo' returns 'No such user'. As soon as I stop nscd, 'id foo' starts working again. I suspect nscd is only looking at /etc/passwd because 'id root' always works (root is present in /etc/passwd). This is on a CentOS 5 system. Disabling SELinux did not help. I did not attach any config files purposefully because I don't know where to look for the problem and attaching nsswitch.conf, ldap.conf etc. would result in a huge post. Nevertheless, I will consider any information needed to diagnose the problem although I suspect that this a very simple configuration problem. Thank you very much :-) fs

3 8

3Ware 9550SX and latency/system responsiveness
by Simon Banton 08 Oct '07

08 Oct '07

Dear list, I thought I'd just share my experiences with this 3Ware card, and see if anyone might have any suggestions. System: Supermicro H8DA8 with 2 x Opteron 250 2.4GHz and 4GB RAM installed. 9550SX-8LP hosting 4x Seagate ST3250820SV 250GB in a RAID 1 plus 2 hot spare config. The array is properly initialized, write cache is on, as is queueing (and supported by the drives). StoreSave set to Protection. OS is CentOS 4.5 i386, minimal install, default partitioning as suggested by the installer (ext3, small /boot on /dev/sda1, remainder as / on LVM VolGroup with 2GB swap). Firmware from 3Ware codeset 9.4.1.2 in use, firmware/driver details: //serv1> /c0 show all /c0 Driver Version = 2.26.05.007 /c0 Model = 9550SX-8LP /c0 Memory Installed = 112MB /c0 Firmware Version = FE9X 3.08.02.005 /c0 Bios Version = BE9X 3.08.00.002 /c0 Monitor Version = BL9X 3.01.00.006 I initially noticed something odd while installing 4.4, that writing the inode tables took a longer time than I expected (I thought the installer had frozen) and the system overall felt sluggish when doing its first yum update, certainly more sluggish than I'd expect with a comparatively powerful machine and hardware RAID 1. I tried a few simple benchmarks (bonnie++, iozone, dd) and noticed up to 8 pdflush commands hanging about in uninterruptible sleep when writing to disk, along with kjournald and kswapd from time to time. Loadave during writing climbed considerably (up to >12) with 'ls' taking up to 30 seconds to give any output. I've tried CentOS 4.4, 4.5, RHEL AS 4 update 5 (just in case) and openSUSE 10.2 and they all show the same symptoms. Googling around makes me think that this may be related to queue depth, nr_requests and possibly VM params (the latter from https://bugzilla.redhat.com/show_bug.cgi?id=121434#c275). These are the default settings: /sys/block/sda/device/queue_depth = 254 /sys/block/sda/queue/nr_requests = 8192 /proc/sys/vm/dirty_expire_centisecs = 3000 /proc/sys/vm/dirty_ratio = 30 3Ware mentions elevator=deadline, blockdev --setra 16384 along with nr_requests=512 in their performance tuning doc - these alone seem to make no difference to the latency problem. Setting dirty_expire_centisecs = 1000 and dirty_ratio = 5 does indeed reduce the number of processes in 'b' state as reported by vmstat 1 during an iozone benchmark (./iozone -s 20480m -r 64 -i 0 -i 1 -t 1 -b filename.xls as per 3Ware's own tuning doc) but the problem is obviously still there, just mitigated somewhat. The comparison graphs are in a PDF here: http://community.novacaster.com/attach.pl/7411/482/iozone_vm_tweaks_xls.pdf Incidentally, the vmstat 1 output was directed to an NFS-mounted disk to avoid writing it to the arry during the actual testing. I've tried eliminating LVM from the equation, going to ext2 rather than ext3 and booting single-processor all to no useful effect. I've also tried benchmarking with different blocksizes from 512B to 1M in powers of 2 and the problem remains - many processes in uninterruptible sleep blocking other IO. I'm about to start downloading CentOS 5 to give it a go, and after that I might have to resort to seeing if WinXP has the same issue. My only real question is "where do I go from here?" I don't have enough specific tuning knowledge to know what else to look at. Thanks for any pointers. Simon

7 56

Asterisk
by Kenneth Porter 06 Oct '07

06 Oct '07

Is an RPM for Asterisk (the PBX system) available for CentOS 5? It looks like RPMforge is supposed to have one, as I can see dependent packages like asterisk-sounds, but the base package seems to be absent from the repository.

5 7

remote tar via ssh
by ann kok 06 Oct '07

06 Oct '07

Hi all Can I use ssh to have remote tar files from machine A to machine B? ssh from machine A to machine B tar all files in machine B to exact to machine A Thank you ____________________________________________________________________________________ Got a little couch potato? Check out fun summer activities for kids. http://search.yahoo.com/search?fr=oni_on_mail&p=summer+activities+for+kids&…

19 51

Jump to page:

2024

2023

2022

2021

2020

2019

2018

2017

2016

2015

2014

2013

2012

2011

2010

2009

2008

2007

2006

2005

2004

Discuss September 2007