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RE: [CentOS] Write performance with 3ware 9550
by Bowie Bailey 13 Oct '06

13 Oct '06

Kirk Bocek wrote: > chrism(a)imntv.com wrote: > > I'm doing this from memory as the machine is at another location > > now. I think I did this: > > > > turned off ncq (per Josh's suggestion) > > turned on write caching (it's on an oversized ups and the data > > isn't critical) set storsave to "performance" > > changed the memory interleave (thanks to kirk's suggestion). It > > was off by default. used parted to create gpt disklabel > > set noatime and one other option that was suggested here for the > > RAID partition used mke2fs -j -b 4096 /dev/blah > > > > That was it. > > Okay, now try installing kernel-module-xfs and xfsutils (located in > the centosplus repository), run mkfs.xfs on some unused space, mount > and re-run bonnie++. I'm sure that would be faster, but I'm sticking to ext3 for now. -- Bowie

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RE: [CentOS] Write performance with 3ware 9550
by Bowie Bailey 13 Oct '06

13 Oct '06

Kirk Bocek wrote: > What's the motherboard or manufacturer and model? Knew I was forgetting something... :) OS: CentOS-4.4 (fully patched) Motherboard: Tyan Thunder K8HM CPU: dual Opteron 280 Memory: 16GB Raid card: 3ware 9550SX-8LP Raid volume: 4-disk Raid 5 with NCQ and Write Cache enabled -- Bowie

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RE: [CentOS] Write performance with 3ware 9550
by Bowie Bailey 13 Oct '06

13 Oct '06

Kirk Bocek wrote: > chrism(a)imntv.com wrote: > > To what end? I'd absolutely NEVER use it in production that way. > > That's *plenty* fast for me. > > On the current system I built, the best I could get from ext3 on a > 4-drive raid-5 array was 95MB/Sec writes. With XFS I'm getting > 220MB/Sec+. For a media server, I want the extra speed. For me, ext3 on a 4-drive raid5 array is 20MB/Sec. I've GOT to be doing something wrong. -- Bowie

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Welcome to the team
by Lance Davis 13 Oct '06

13 Oct '06

I would like to formally welcome Matthew Martz to the CentOS team, he has volunteered to take on the role of Mirror Administrator, so hopefully things will get done quicker now we have a dedicated person and I would like to express all of our thanks to Matthew for stepping in to this role. If you are interested in volunteering to help with CentOS and have skills that you think we need , take a look at http://wiki.centos.org/HowToContribute and see if there are things there that you could help with - we will try to keep the list up to date. Regards Lance Davis CentOS Project Leader -- uklinux.net - The ISP of choice for the discerning Linux user.

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Recommend dedicated CentOS hosting?
by Gustaf Alströmer 13 Oct '06

13 Oct '06

Hello, Can anyone recommend a pure dedicated US-based hosting with CentOS support? Prefeably one that is flexible when you need to scale the system. Anywhere I can find user-reviews? Thanks, Gustaf

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RE: [CentOS] Write performance with 3ware 9550
by Bowie Bailey 13 Oct '06

13 Oct '06

chrism(a)imntv.com wrote: > Kirk Bocek wrote: > > I saw a definite improvement by turning off NCQ and setting StorSave > > to 'Balanced.' Are these 1.5GB/Sec or 3.0GB/Sec SATA drives? During > > my testing I changed from non-interleaved memory and 1.5GB to > > interleaved and 3.0GB. Made a big difference in bonnie++ results. > > Unfortunately, I can't say which was more important. > > > > If you have the patience, read through my recent (but lengthy) > > thread on the 3Ware 9550 titled "Calling All FS Fanatics." There's > > a lot of good info from many helpful people. I've only gotten full > > performance using JFS or XFS. > > > > I'm doing this from memory as the machine is at another location now. > I think I did this: > > turned off ncq (per Josh's suggestion) Tried that, it made a small improvement (see my previous post). > turned on write caching (it's on an oversized ups and the data isn't > critical) Write caching is on. I've got a BBU, so the data is protected. > set storsave to "performance" I prefer to leave this one as is to take advantage of the write journaling. > changed the memory interleave (thanks to kirk's suggestion). It was > off by default. This one I would like to try. Can you tell me where I can make the change? > used parted to create gpt disklabel What is the advantage of gpt over msdos? Can I make this change without recreating the filesystem? > set noatime and one other option that was suggested here for the RAID > partition Anyone know if noatime is recommended for a filesystem containing an Oracle database? What was the other option? > used mke2fs -j -b 4096 /dev/blah I used 'mkfs.ext3 /dev/blah'. It created 4K blocks. > That was it. > > Also, I tried the same array as a RAID0 device on the same box and the > performance was approximately the same (maybe ever so slightly > faster). Raid0 should be faster, particularly with writes since it doesn't have to calculate parity. -- Bowie

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RE: [CentOS] Write performance with 3ware 9550
by Bowie Bailey 13 Oct '06

13 Oct '06

Non-interleaved memory sounds interesting. Where do I change that setting? I don't want to change the StorSave setting. I'm not really looking for maximum performance here, just reasonable. If I can get the same 60 M/s speed that I got from the first server, I'll be happy. The drives are all running at 3.0GB/Sec according to the drive information in 3DM. I have read the entire "Calling All FS Fanatics" thread as it passed through the list. It was quite interesting, but the main things I got from it are: - Increase the read ahead settings - XFS, JFS, and ReiserFS are faster, but less fault-tolerant, than ext3 I have already changed the read ahead on both the physical volume and the logical volume. This gives me increased read performance, but has no effect on writes. I am sticking with ext3 since I am much more concerned about stability than performance. Bowie Kirk Bocek wrote: > I saw a definite improvement by turning off NCQ and setting StorSave > to 'Balanced.' Are these 1.5GB/Sec or 3.0GB/Sec SATA drives? During > my testing I changed from non-interleaved memory and 1.5GB to > interleaved and 3.0GB. Made a big difference in bonnie++ results. > Unfortunately, I can't say which was more important. > > If you have the patience, read through my recent (but lengthy) thread > on the 3Ware 9550 titled "Calling All FS Fanatics." There's a lot of > good info from many helpful people. I've only gotten full performance > using JFS or XFS. > > Kirk Bocek > > Bowie Bailey wrote: > > I have two identical servers. The only difference is that the first > > one has Maxtor 250G drives and the second one has Seagate 320G > > drives. > > > > OS: CentOS-4.4 (fully patched) > > CPU: dual Opteron 280 > > Memory: 16GB > > Raid card: 3ware 9550Sx-8LP > > Raid volume: 4-disk Raid 5 with NCQ and Write Cache enabled > > > > On the first server I have decent performance. Nothing spectacular, > > but good enough. The second one has about 1/3 the write speed. I > > can't find any difference between the systems. Both of them have > > the same stripe size, both have ext3 filesystems, both have write > > caching and NCQ turned on. I have already increased the read ahead > > setting to 16384 on both servers. > > > > I ran the tests like this: > > > > # sync; bonnie++ -d /iotest -s 50g -n 0 -b -f > > (I have removed some extra information from the reports for brevity) > > > > And here are the results for the two servers: > > > > ------Output------- --Input-- > > --Block-- -Rewrite- --Block-- --Seeks-- > > Machine Size K/sec %CP K/sec %CP K/sec %CP /sec %CP > > First 50G 62893 25 46763 12 160672 19 120.6 1 > > Second 50G 18835 7 44025 12 194719 24 122.8 1 > > > > As you can see, the write performance of the second server is > > terrible. Anyone have any suggestions of what I can look for? I > > keep thinking there must be something I tweaked on the first server > > that I forgot about for the second one, but so far I haven't been > > able to find it. > > > > Any suggestions appreciated!

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Live CD Build Error
by Faysal Banna 13 Oct '06

13 Oct '06

Good day Guys I have worked around that Problem with yum and statically specified the release as 4.4 CentOS but now another problem with chroot arises . when i chroot chroot $LIVE chroot: cannot run command `/bin/bash': No such file or directory and to display the ls $LIVE/bin/ alsaunmute dd gtar mknod rpm traceroute arch df gunzip mktemp rvi traceroute6 ash dmesg gzip more rview true ash.static dnsdomainname hostname mount sed umount awk doexec igawk mt setfont uname basename domainname ipcalc mv setserial unicode_start bash dumpkeys kbd_mode netstat sh unicode_stop bsh echo kill nice sleep unlink cat ed ksh nisdomainname sort usleep chgrp egrep link pgawk stty vi chmod env ln ping su view chown ex loadkeys ping6 sync ypdomainname cp false login ps tar zcat cpio fgrep ls pwd tcsh csh gawk mail red touch cut gettext mailx rm tracepath date grep mkdir rmdir tracepath6 Regards. .... 'Good day Sir. 'I am trying to do LiveCD as described in Scientific Linux Live CD Page <http://linux.web.psi.ch/livecd/build.html> Yet i fail.... 'the system is running CentOs kernel 2.6.9-42.0.2.plus.c4smp 'with 8GB ram and two CPU's each Duo Core 64bit ' 'the error is nevertheless due to yum installation as described in your posted message. 'root@H-1 Build# yum -c $LIVE/etc/yum.conf --installroot=$LIVE install yum rootfiles shadow-utils \ '> bind-utils gnupg vim-enhanced vixie-cron crontabs passwd which kudzu dhclient \ '> pciutils eject alsa-utils mkisofs wget 'Setting up Install Process 'Setting up repositories 'not using ftp, http[s], or file for repos, skipping - Null is not a valid release or hasnt been released yet 'Cannot find a valid baseurl for repo: update 'Error: Cannot find a valid baseurl for repo: update 'root@H-1 Build# 'Regards 'Faysal Banna 'Meteorological Services 'Rafic Hariri International Airport 'Beirut - Lebanon 'Phone +961-1-628160 ' +961-3-258043 '

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Training Material: Books about linux but targeting Centos installations
by Erick Perez 13 Oct '06

13 Oct '06

Hi, I am about to give a training session in Linux, using Centos 4.4 as a base. I want to give my students (MS windows administrators) printed books about Linux and hopefully Centos based. It is a total of 20 books. I'm also interested in purchasing 20 copies of the DVD of Centos 4.4 x86/x86_64 distro. My initial search at amazon returned no useful results. It can be RHEL 4, Centos 4 or fedora 4 based but I really want them to be Centos if possible, given the fact that I often scracth RHEL intallations in favor of Centos (i know is the same base, but I would like to match the book with the distro). The books have to be focused to Linux administration and installation (like web,ssh.mail.etc). There is no need to cover in-depth programming (perl,bash,etc). Can anyone in the Centos community have some references of these books/DVDs for purchase? Thanks, -- ------------------------------------------------------------ Erick Perez Panama Sistemas Integradores de Telefonia IP y Soluciones Para Centros de Datos Panama, Republica de Panama Cel Panama. +(507) 6694-4780 ------------------------------------------------------------

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RE: [CentOS] Write performance with 3ware 9550
by Bowie Bailey 13 Oct '06

13 Oct '06

chrism(a)imntv.com wrote: > Bowie Bailey wrote: > > Joshua Baker-LePain wrote: > > > On Thu, 12 Oct 2006 at 4:22pm, Bowie Bailey wrote > > > > > > > I have two identical servers. The only difference is that the > > > > first one has Maxtor 250G drives and the second one has Seagate > > > > 320G drives. > > > > > > > > OS: CentOS-4.4 (fully patched) > > > > CPU: dual Opteron 280 > > > > Memory: 16GB > > > > Raid card: 3ware 9550Sx-8LP > > > > Raid volume: 4-disk Raid 5 with NCQ and Write Cache enabled > > > > > > > > On the first server I have decent performance. Nothing > > > > spectacular, but good enough. The second one has about 1/3 the > > > > write speed. I can't find any difference between the systems. > > > > Both of them have the same stripe size, both have ext3 > > > > filesystems, both have write caching and NCQ turned on. I have > > > > already increased the read ahead setting to 16384 on both > > > > servers. > > > Turn off NCQ. Last I knew, this was still 3ware's recommendation. > > > > I can try that, but when I tested on the first server, I found that > > disabling NCQ increased the read performance by 10M/s and decreased > > the write performance by 10M/s. Maybe I'll get different results > > from the Seagate drives. > > Here's what I'm getting from a dual Opteron 275 box, Centos 4.4-64bit, > 2gb RAM and an 8 drive array of 750gig Seagates: > > 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 > localhost.locald 4G 248901 96 138957 40 308874 > 42 625.8 > > I've been applying all the various tricks that came up during the last > couple of threads. Turning NCQ off definitely made a big difference > for me. With NCQ off, I get these results: 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 Second 50G 20853 8 41899 11 192713 23 116.9 1 Write performance increased by 2M/s and read performance decreased by 2M/s. What tweaks have you applied so far? I would expect a 4-drive array to be slower than an 8-drive array, but not this much! -- Bowie

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