Weird, seems as if the faster the processor the longer the test takes. I ran it on 2 other machines, in addition to the one with raid. Here are the results. What type of disks are you using? Your results are almost twice as fast as my fastest (which is machine 3 i.e. my slowest chip speed). Jay Machine 1 (the one in question), AMD 3200, 1 GB RAM, Disks on individual IDE channels platinum:~# df Filesystem 1K-blocks Used Available Use% Mounted on /dev/md0 19686680 1195512 17491132 7% / tmpfs 452284 0 452284 0% /dev/shm /dev/md1 39373624 32844 37340696 1% /opt /dev/md2 39373624 32848 37340692 1% /home /dev/md4 14974680 32872 14181136 1% /usr/local platinum:~# time dd if=/dev/hda of=/dev/null bs=64k count=10000 10000+0 records in 10000+0 records out 655360000 bytes transferred in 166.335481 seconds (3939989 bytes/sec) real 2m46.336s user 0m0.004s sys 2m13.280s platinum:~# time dd if=/dev/hdc of=/dev/null bs=64k count=10000 10000+0 records in 10000+0 records out 655360000 bytes transferred in 171.632623 seconds (3818388 bytes/sec) real 2m51.634s user 0m0.004s sys 1m33.162s # Machine 2, PII 400 Mhz, the disks are master/slave meir:~# df Filesystem 1k-blocks Used Available Use% Mounted on /dev/hda4 4806936 1220040 3342708 27% / /dev/hda1 46636 935 43293 3% /boot /dev/hda5 4996728 938156 3804748 20% /home /dev/hda6 3937220 2026628 1710588 55% /usr /dev/hdb2 9843308 8246848 1096440 89% /opt au:/usr/local/src 29530400 6731216 21299120 25% /usr/local/src meir:~# time dd if=/dev/hda of=/dev/null bs=64k count=10000 10000+0 records in 10000+0 records out real 2m48.300s user 0m0.030s sys 1m49.000s Machine 1, PPro 180 Mhz, Master/Slave abba:~# df Filesystem 1K-blocks Used Available Use% Mounted on /dev/hda1 9851308 2534948 6815940 28% / tmpfs 258204 0 258204 0% /dev/shm /dev/hda3 7842996 3502032 3942552 48% /mnt/hda3 abba:~# time dd if=/dev/hda of=/dev/null bs=64k count=10000 10000+0 records in 10000+0 records out 655360000 bytes transferred in 56.396242 seconds (11620632 bytes/sec) real 0m56.416s user 0m0.120s sys 0m11.960s ----- Original Message ----- From: "Guy" <bugzilla@watkins-home.com> To: <me@heyjay.com> Sent: Thursday, May 06, 2004 9:44 PM Subject: RE: Sync rates? > My system re-builds at 4000-5000K/sec/disk. It has 14 disks. > During a re-build the CPU load is below 5%. > I have 2 CPUs, P3-500Mhz, 512Meg ram. > During a re-build I don't notice any slowdown. I had a disk fail and it > re-build on the spare. I did not know until hours after it was done. > > If you cat /proc/mdstat it will show the re-build rate. > That rate is per disk, not an overall total. > > I would say your system has problems! > Test each disk with dd. > This is a read test!! > > time dd if=/dev/hda of=/dev/null bs=64k count=10000 > > This should take less than a minute (34.6 seconds for me). > If the above gives the same results on each disk, drop the count=10000. > > time dd if=/dev/hda of=/dev/null bs=64k > > Without the count=10000 it will read 100% of the disk, this may take an hour > or more. > It will report a record count. > Do this math to determine the speed in K per second. > Records*64/number of seconds > > Replace "hda" with whatever is correct for you. > Do this for each disk. > I bet you find 1 disk is much slower than the others. > Maybe a bad cable, don't know. > > Good luck, > Guy > > -----Original Message----- > From: linux-raid-owner@vger.kernel.org > [mailto:linux-raid-owner@vger.kernel.org] On Behalf Of me@heyjay.com > Sent: Thursday, May 06, 2004 10:02 PM > To: Paul Clements > Cc: linux-raid@vger.kernel.org > Subject: Re: Sync rates? > > My machine was idle during the rebuild. When I say idle, I mean no one > logged in, no user processes running (except me sshed into the box), no > database, no I/O other than the rebuild. > > While the rebuild was going on my system was debilitated, totally slow to > respond to ssh commands > > Jay > ----- Original Message ----- > From: "Paul Clements" <paul.clements@steeleye.com> > To: <me@heyjay.com> > Cc: <linux-raid@vger.kernel.org> > Sent: Thursday, May 06, 2004 2:59 PM > Subject: Re: Sync rates? > > > > me@heyjay.com wrote: > > > > > platinum:~# cat /proc/sys/dev/raid/speed_limit_min > > > 1000 > > > platinum:~# cat /proc/sys/dev/raid/speed_limit_max > > > 200000 > > > Are these acceptable? > > > > Well, those values are in KB/s. And, your resync rate is about: > > > > 120000000 / ( 24 * 60 * 60 ) = 1388 KB/s > > > > if my calculations are correct. I'd try bumping the min value up to say > > 10000 and see if that speeds things up. Is there much I/O activity on > > the system? That will slow down a resync quite a bit, too. > > > > -- > > Paul > > > > > > - > To unsubscribe from this list: send the line "unsubscribe linux-raid" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > > > > - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
