[SOLVED] Re: mpt errors - UNIT ATTENTION asc:29,0

A bit more digging showed that these mpt errors match
UDMA_CRC_Error_Count reported by drives via SMART.
Connecting the same drives with the same cables to ICH7 SATA ports
completely eliminates the errors which suggests that drives and cables
themself are OK.
So, my guess is that there's fair amount of cross-talk between LSI1068
ports on the motherboard (Asus P5BV/SAS).

In the end I've switched on spread spectrum clocking on the drives
(jumper 1-2 on WD SATA drives) and the errors almost completely
disappeared. I've got 1 CRC error vs hundreds there used to be after
~10TB have been read/written.

What didn't quite work:
* Forcing drives into 1.5Gb mode (jumper 5-6 on WD drives). Errors
became somewhat less frequent, but didn't go away.
* replacing SATA cables -- tried three different sets with virtually
no change in error rate.

--Artem



On Fri, Aug 7, 2009 at 11:06 AM, Artem Belevich<artemb_at_gmail.com> wrote:
> Hi,
>
> I'm running 8.0-BETA2 on Asus p5BV/SAS with built-in LSI1068
> controller with 8 SATA ports. 6 of the ports hooked up to 1TB WD Green
> drives. The drives are used as a single raidz2 ZFS pool:
>
>        NAME        STATE     READ WRITE CKSUM
>        z2          ONLINE       0     0     0
>          raidz2    ONLINE       0     0     0
>            da1     ONLINE       0     0     0
>            da0     ONLINE       0     0     0
>            da2     ONLINE       0     0     0
>            da3     ONLINE       0     0     0
>            da4     ONLINE       0     0     0
>            da5     ONLINE       0     0     0
>
> I'm runing a simple stress test that copies 10GB file until it fills
> the volume and then runs "zfs scrub" on it.
>
> dd if=/dev/urandom of=/z2/f.0 bs=1m count=10240
> for f in {1..350}; do echo $f; cp f.$[$f-1] f.$f; done;
> zpool scrub z2
>
> What concerns me is that I'm periodically getting error messages from
> MPT driver. They usually start few hours after the start of the script
> and by the end of it they are happening every few minutes seemingly
> randomly on all six drives.
>
> Aug  7 10:25:32 buz kernel: mpt0: mpt_cam_event: 0x16
> Aug  7 10:25:32 buz kernel: mpt0: mpt_cam_event: 0x16
> Aug  7 10:25:32 buz kernel: (da4:mpt0:0:4:0): READ(10). CDB: 28 0 46
> 32 97 c0 0 0 80 0
> Aug  7 10:25:32 buz kernel: (da4:mpt0:0:4:0): CAM Status: SCSI Status Error
> Aug  7 10:25:32 buz kernel: (da4:mpt0:0:4:0): SCSI Status: Check Condition
> Aug  7 10:25:32 buz kernel: (da4:mpt0:0:4:0): UNIT ATTENTION asc:29,0
> Aug  7 10:25:32 buz kernel: (da4:mpt0:0:4:0): Power on, reset, or bus
> device reset occurred
> Aug  7 10:25:32 buz kernel: (da4:mpt0:0:4:0): Retrying Command (per Sense Data)
>
> ZFS scrub does not seem to report any issues so far - no checksum or
> read/write errors. WD's hard drive diagnostics tools didn't find any
> issues with te drives either.
>
> Sould somebody shed some light on why would such error happen? Is that
> some sort of hardware issue? Driver bug? Issue with compatibility
> between controller and the drives? System configuration issue (some
> sysctl/tunable needs tweaking, perhaps)?
>
> I'd appreciate any hints on what could be going on and what should be
> done about it.
>
> Thanks,
> --Artem
>