-----Original Message----- From: linux-scsi-owner@xxxxxxxxxxxxxxx [mailto:linux-scsi-owner@xxxxxxxxxxxxxxx] On Behalf Of James Bottomley Sent: Monday, 29 October 2007 1:27 AM To: Anthony Ewell Cc: linux-scsi Subject: Re: slow after upgrade to CentOS 5 (RHEL5) On Sat, 2007-10-27 at 13:21 -0700, Anthony Ewell wrote: > James Bottomley wrote: > > On Wed, 2007-10-24 at 18:04 -0700, Anthony Ewell wrote: > >> Hi All, > >> > >> If you all would not mind a post from the general > >> public Linux user, after doing a complete disk wipe > >> of CentOS 4 and installing CentOS5, my system is preceived > >> to be 3 times slower. > >> > >> To troubleshooting this, I made a post on CentOS's > >> bugzilla: http://bugs.centos.org/view.php?id=2382 > >> > >> Would some of the experts on this group mind > >> looking at the bug to evaluate the possibility > >> that it is being caused by the underlying scsi > >> driver? The post contains a dmesg from "Computer C". > >> (Yes, I am getting a bit desperate.) > > > > There's still too little information in the bug report to tell much of > > anything. The dmesg doesn't indicate any anomaly with the megaraid > > (although the LSI people might be able to tell better). However, it > > also doesn't contain a trace of the tape drive. > > > > Best guess would be a slow down in the megaraid driver. Can you try > > doing a speed test on it? (hdparm -t should suffice). > > > > James > > > Hi James, > > The other guy reporting the problem > > http://www.centos.org/modules/newbb/viewtopic.php?topic_id=10659&start=0 #forumpost34209 > is not using a MegaRAID card. He is using 3ware9508 Raid Controllers. > He is also using a different processor (amd vs xeon) and a different > chipset (Intel Greenwood vs nVidia) > > I also spoke to Neela Kolli (Mega RAID maintainer) and he said he'd > never heard of the problem. Here are some tests (including dhparm) > that I sent to Neela (he never wrote back). > > I have also checked with Stellen over at the "dump" > list and he has not seen the problem (yet). > > The problem occurs when backing up to a two different types > of tape drives and to an eSata drive. > > When I am running a "dump" on computer C, gnome-system-monitor > shows my two cores running at only about 10 to 20% and > switching back and forth (one at 0% the other at 20% for > about 5 seconds, then switching positions) > > On Computer C (Cent OS 5), when typing in Word Pro (a windows word > processor) in Parallels, I can watch myself type. Computer B > (CentOS 4.4, now 4.5) has the same version of Parallels > installed on it (Parallels-2.2.2112-lin.i386) that computer C > (CentOS 5) has. The perceived speed difference is about a factor > of three (you can not watch yourself type). > > All the "Low Level" test I run seem to come out the same between > Cent OS 4.4 and 5. Very frustrating! It is almost like some > system monitor component is looking at everything and > slowing things down. If this was Windows, I'd go straight > to the Anti Virus as the culprit. (Does SE Linux do such > things?) > > Are there any performance tests I can run for you? > > Thank you for letting me ramble, this problem is > really frustrating. I am afraid to any additional CentOS5 > server out there and CentOS 4.x is so terribly out of > date. > > -T > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > Tests I sent to Neela: > > CentOS 5 (2.6.18-8.1.8.el5, Sata150-4): > > #grep -i bogomips /var/log/dmesg > Calibrating delay using timer specific routine.. 4001.91 BogoMIPS > (lpj=2000959) > Calibrating delay using timer specific routine.. 3999.58 BogoMIPS > (lpj=1999791) > Total of 2 processors activated (8001.50 BogoMIPS). > > > #/sbin/hdparm -t /dev/sda > /dev/sda: > Timing buffered disk reads: 236 MB in 3.01 seconds = 78.53 MB/sec > > > #/sbin/hdparm -t /dev/sdb > /dev/sdb: > Timing buffered disk reads: 182 MB in 3.01 seconds = 60.37 MB/sec > > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > CentOS 4.4 (linux rescue 2.6.9-42.EL, IDE): > > #cat /proc/cpuinfo > bogomips : 4002.92 > > #/sbin/hdparm -t /dev/sda > /dev/sda: > Timing buffered disk reads: 216 MB in 3.01 seconds = 71.87 MB/sec > > #/sbin/hdparm -t /dev/sdb > /dev/sdb: > Timing buffered disk reads: 184 MB in 3.01 seconds = 61.18 MB/sec That pretty much shows, if anything, that transfer speed improved from .9 to .18. > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > CentOS 5 (2.6.18-8.1.3.el5, Sata300-4): > #grep -i bogomips /var/log/dmesg > Calibrating delay using timer specific routine.. 4001.92 BogoMIPS > (lpj=2000960) > Calibrating delay using timer specific routine.. 3999.58 BogoMIPS > (lpj=1999794) > Total of 2 processors activated (8001.50 BogoMIPS). > > #/sbin/hdparm -t /dev/sda > /dev/sda: > Timing buffered disk reads: 214 MB in 3.02 seconds = 70.86 MB/sec > > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > CentOS 5 (2.6.18-10.1.3.el5, Sata300-4): > > eSata: dump -0a -z -f /dev/nul winxp.hdd ^^^^^^^^ Typo ? Shouldn't that be /dev/null Regards Mark [snip] - To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html - To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
