Messages in this thread | | | Date | Fri, 28 Feb 2003 11:03:52 -0700 | From | kwijibo@zianet ... | Subject | Re: Slowing down disk access? |
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I have nearly an identical system as yours. Dual 1.6 Athlons, two 3ware 7850's, 8 disks on each but with 160 gig drives. I have kernel 2.4.19 on it with ext3. My RAID is arranged slightly different however. I have each controller do a RAID 5 and then I software mirror the two. This box gets hammered pretty hard at times over NFS and other services but I have never seen this type of behaviour come out of it. Are you sure one of your drives isn't going bad, it looks the error is always coming from unit #7. Do all of them do this?
Steve
Robert L. Harris wrote:
> I've got a system I need to slow down disk access on it would seem. The >syerver, a dual 1.5Ghz Athalon has two 3ware IDE controllers, 8 disks >each for a total of sixteen 180 Gig disks. This system is laid out in >four RAID5 arrays that it shares out via NFS. kernel 2.4.19-ac4, ext3 >file systems. I've got 7 of these. > > This works great and provides a LOT of cheap disk that we use for >staging backups before cloning off to tape. > > The problem is that when the array's get pounded HARD, such as when >legato is cleaning it's file devices (nsrstage -C) the machine will lock >up and spew errors to my console: > >3w-xxxx: scsi1: Command failed: status = 0xc7, flags = 0x1b, unit #7. >3w-xxxx: scsi1: Command failed: status = 0xc7, flags = 0x1b, unit #7. >3w-xxxx: scsi1: Command failed: status = 0xc7, flags = 0x1b, unit #7. >3w-xxxx: scsi1: Command failed: status = 0xc7, flags = 0x1b, unit #7. >3w-xxxx: scsi1: Command failed: status = 0xc7, flags = 0x1b, unit #7. >3w-xxxx: scsi1: Command failed: status = 0xc7, flags = 0x1b, unit #7. >3w-xxxx: scsi1: Command failed: status = 0xc7, flags = 0x1b, unit #7. >3w-xxxx: scsi1: Command failed: status = 0xc7, flags = 0x1b, unit #7. >3w-xxxx: scsi1: Command failed: status = 0xc7, flags = 0x1b, unit #7. >3w-xxxx: scsi1: AEN: WARNING: ATA port timeout: Port #7. >3w-xxxx: scsi1: AEN: WARNING: ATA port timeout: Port #7. >3w-xxxx: scsi1: AEN: WARNING: ATA port timeout: Port #7. >3w-xxxx: scsi1: AEN: WARNING: ATA port timeout: Port #7. >3w-xxxx: scsi1: AEN: WARNING: ATA port timeout: Port #7. >3w-xxxx: scsi1: AEN: WARNING: ATA port timeout: Port #7. >3w-xxxx: scsi1: AEN: WARNING: ATA port timeout: Port #7. >3w-xxxx: scsi1: AEN: WARNING: ATA port timeout: Port #7. > > This requires a hard reboot. If I use the magic keys and reset it then >it goes down but doesn't come back up properly, usually dieing around >the LILO area, I believe the array or disks are left in an odd state. > > Is there a way to actually slow down the disk access/read/write other >than re-making the filesystems? On the other systems the chunk size is >at either 32K or 128K. On this one in particular the chunk size is >1024K which was determined by running a number of tests (bonnie, nfs >reads/writes) and was found to be about the fastest for our money's >worth. The disk hangups didn't appear until just recently. If there's >no other choise I can leave the disks as read only until the data rolls >off then remake them in 32 or 64K. > >Any other thoughts? > Robert > > > >:wq! >--------------------------------------------------------------------------- >Robert L. Harris | PGP Key ID: E344DA3B > @ x-hkp://pgp.mit.edu >DISCLAIMER: > These are MY OPINIONS ALONE. I speak for no-one else. > >Diagnosis: witzelsucht > >IPv6 = robert@ipv6.rdlg.net http://ipv6.rdlg.net >IPv4 = robert@mail.rdlg.net http://www.rdlg.net > >
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