Re: SB700 AHCI causes disk power cycle

[Tejun Heo <tj@kernel.org>]

Hello,

wessels wrote:
> Hi,
> 
> I also bought an ASUS M3A78 mATX board with a SB700 to see if it might
> solve my problem with the SB600. But it doesn't.
> The SB700 shows the same behaviour as the SB600, it periodically
> throws an error and the power cycles the disk.
> But it always happens on one channel not both. Perhaps a sudden burst
> in disk IO causes this but I'm unable to
> reproduce this with a synthetic load. Only when vmware is running this
> happens. I don't see it when the machine is idling.
> The load on the machine is very light both on cpu and disk. Also I
> didn't see the error with a single seagate disk attached.
> 
> The error and configuration is the same as mentioned in my earlier
> post regarding the "SB600 AHCI causes disk power cycle".
> 
> What I didn't mentioned then was the filesystem layout
> two disks in a mirror
> /dev/sda & /dev/sdb
> no LVM just a software raid via md
> md0 /boot ext3
> md1 / ext3
> md2 swap
> md3 /usr/local/virtmach XFS
> 
> Please let me know what else I need to log and/or test.

>From your report on sb600.

kernel: ata4: SError: { RecovComm Persist PHYRdyChg 10B8B }
kernel: ata4.00: cmd ea/00:00:00:00:00/00:00:00:00:00/a0 tag 0
kernel:          res 40/00:3c:0d:bd:c9/00:00:0b:00:00/40 Emask 0x10 (ATA bus error)

This combined with the incremented start stop count looks very much
like the harddisk went offline briefly and came back for whatever
reason.  I doubt the ahci driver even with its all might can do that.

Can you please try to hook up the faulting harddrive to a separate
power supply?

  http://modtown.co.uk/mt/article2.php?id=psumod

-- 
tejun