Re: Panics after AHCI timeouts

On Wed, 26 Oct 2011 16:00:55 +0200
"C. P. Ghost" <cpghost_at_cordula.ws> wrote:

> On Wed, Oct 26, 2011 at 2:27 AM, Alexander Kabaev <kabaev_at_gmail.com>
> wrote:
> > I do see timeouts on one of my Samsung ST3750330A disks and they
> > definitely do not cause any panics. The weird part in my case is
> > that disk then immediately reappears as online and mirror zpool can
> > be rebuilt by just onlining the disk with 'zpool online <pool>
> > <disk>' command.
> >
> > It seems to be happening once system has accumulated some uptime. If
> > rebooted, it keeps running for a week or two with no issues, but
> > then timeouts start to happen more or less reliably every single 24
> > hours.
> 
> Does it correlate with high disk activity, i.e. with periodic(8)?
> 
> On my machine, I have a feeling that timeouts occur more often
> at that point, than normally... and that they also occur when multiple
> processes access the disk simultaneously.
> 
> If it's only one process, the machine (usually) doesn't hang, even
> when that process is copying big files back and forth for a long
> period of time (it's a backup process). But interleave that process
> with another one accessing the same disk, and poof!, almost
> immediately ahci timeouts. occur. Very strange... Maybe a race
> condition of some sort after all?
> 

No, I cannot say there is any specific correlation to IO load of the
machine, timeouts I saw happen randomly and seem almost always happen
as system uptime crosses two weeks boundary. I am suspecting Samsung
firmware at this point.

-- 
Alexander Kabaev