linux-kernel - Re: MD/RAID time out writing superblock

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <4A9BC033.9000909@pobox.com>
Date:	Mon, 31 Aug 2009 08:21:07 -0400
From:	Mark Lord <mlord@...ox.com>
To:	Tejun Heo <tj@...nel.org>
CC:	Ric Wheeler <rwheeler@...hat.com>, Andrei Tanas <andrei@...as.ca>,
	NeilBrown <neilb@...e.de>, linux-kernel@...r.kernel.org,
	IDE/ATA development list <linux-ide@...r.kernel.org>,
	linux-scsi@...r.kernel.org, Jeff Garzik <jgarzik@...hat.com>
Subject: Re: MD/RAID time out writing superblock

Tejun Heo wrote:
> Ric Wheeler wrote:
..
>> The drive might take a longer time like this when doing error handling
>> (sector remapping, etc), but then I would expect to see your remapped
>> sector count grow.
> 
> Yes, this is a possibility and according to the spec, libata EH should
> be retrying flushes a few times before giving up but I'm not sure
> whether keeping retrying for several minutes is a good idea either.
> Is it?
..

Libata will retry only when the FLUSH returns an error,
and the next FLUSH will continue after the point where
the first attempt failed.

But if the drive can still auto-relocate sectors, then the
first FLUSH won't actually fail.. it will simply take longer
than normal.

A couple of those, and we're into the tens of seconds range
for time.

Still, it would be good to actually produce an error like that
to examine under controlled circumstances.

Hmm.. I had a drive here that gave symptoms like that.
Eventually, I discovered that drive had run out of relocatable
sectors, too.  Mmm.. I'll see if I can get it back (loaned it out)
and perhaps we can recreate this specific scenario on it..

Cheers
-- 
Mark Lord
Real-Time Remedies Inc.
mlord@...ox.com
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/