Please don't drop the cc lists. There are others who probably have more informed opinions than I do who won't get to comment if they don't see it. On Sun, 2007-10-28 at 17:36 -0700, Anthony Ewell wrote: > James Bottomley wrote: > > 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 > >> DUMP: Volume 1 took 0:04:04 > >> DUMP: Volume 1 transfer rate: 4247 kB/s > >> DUMP: Volume 1 1567020kB uncompressed, 1036385kB compressed, 1.513:1 > >> > >> eSata: dump -0a -f /dev/nul winxp.hdd (no compression) > >> DUMP: Volume 1 1036420 blocks (1012.13MB) > >> DUMP: Volume 1 took 0:02:09 > >> DUMP: Volume 1 transfer rate: 8034 kB/s > >> > >> > >> 150-4: dump -0a -z -f /dev/nul winxp.hdd > >> DUMP: Volume 1 took 0:04:05 > >> DUMP: Volume 1 transfer rate: 4230 kB/s > >> DUMP: Volume 1 1573150kB uncompressed, 1036383kB compressed, 1.518:1 > >> > >> 150-4: dump -0a -f /dev/nul winxp.hdd (no compression) > >> DUMP: Volume 1 1036420 blocks (1012.13MB) > >> DUMP: Volume 1 took 0:02:05 > >> DUMP: Volume 1 transfer rate: 8291 kB/s > > > > I think this is beginning to point to problems with dump. What are the > > corresponding figures for dump under 2.6.9 (or are the two sets of > > figures centos5 followed by centos4)? > > > > James > > > > Computer C: > backup drive: eSATA > hard drive: RAID SATA-150-4 > > CentOS 4.4, 1:05 hours, approx 52 GB backup file 13,333 kBytes/sec > CentOS 5.0, 3:16 hours, approx 43 GB backup file 3,656 kBytes/sec > Note: 3.6 times slower > > Hi James, > > The above shows the dump speed difference between CentOS 4.4 and > CentOS 5. > > I suspected dump at first, until I noticed everything else > was about 3 times slower too, such as Parallels, etc. Open > Office 2.3 (linux version) opens about 3 times slower. > > Are there any tests you know of to shake out who is > slowing the works down? Yes, could you do backup write tests without dump in the process (as in just do a straight dd from /dev/zero to the devices in centos 4 and 5). If there's no difference in that, it's some scheduling or filesystem issue with dump, I'd expect. > When I get a chance, I am going to run a dump from my > CentOS 5 install DVD in rescue mode (linux rescue). This > to make sure no high level driver is slowing things > down. I will let you know what shows up. James - 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
