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From: "Martin K. Petersen" <martin.petersen@oracle.com>
To: Mike Snitzer <snitzer@redhat.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>,
	device-mapper development <dm-devel@redhat.com>,
	"Alasdair G. Kergon" <agk@redhat.com>,
	linux-scsi@vger.kernel.org
Subject: Re: dm: Integrity errors should not cause failover
Date: Wed, 25 May 2011 11:04:58 -0400	[thread overview]
Message-ID: <yq139k2akit.fsf@sermon.lab.mkp.net> (raw)
In-Reply-To: <20110523181723.GA18971@redhat.com> (Mike Snitzer's message of "Mon, 23 May 2011 14:17:24 -0400")

>>>>> "Mike" == Mike Snitzer <snitzer@redhat.com> writes:

Mike,

Mike> Alasdair and I just chatted about this patch: it will always pass
Mike> the the -EILSEQ up _without_ performing any mpath path failure.

Correct.


Mike> The newfound concern is: is there ever a benefit to failing the
Mike> path before returning -EILSEQ?

No, never.


Mike> Or will -EILSEQ always imply there is nothing wrong with the path?
Mike> E.g. a transport error cannot cause a CRC error -- the transport
Mike> error is always trapped by SCSI and cannot result in continued
Mike> processing of an IO (that goes on to have CRC error)?

-EILSEQ is only returned if a discrepancy is detected between data and
protection information. In both cases the block in question was
successfully received by either initiator or target. I.e. the path is
working fine.

-- 
Martin K. Petersen	Oracle Linux Engineering

  reply	other threads:[~2011-05-25 15:04 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-05-18  4:49 [PATCH] dm: Integrity errors should not cause failover Martin K. Petersen
2011-05-18 12:11 ` Mike Snitzer
2011-05-23 18:17   ` Mike Snitzer
2011-05-25 15:04     ` Martin K. Petersen [this message]
  -- strict thread matches above, loose matches on Subject: below --
2011-03-08  6:54 [PATCH] " Martin K. Petersen
2011-03-08 15:14 ` Mike Snitzer
2011-03-08 15:20   ` James Bottomley
2011-03-08 15:30     ` Mike Snitzer
2011-03-08 15:24   ` Martin K. Petersen

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