From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Martin K. Petersen" Subject: Re: dm: Integrity errors should not cause failover Date: Wed, 25 May 2011 11:04:58 -0400 Message-ID: References: <20110518121156.GB18433@redhat.com> <20110523181723.GA18971@redhat.com> Mime-Version: 1.0 Content-Type: text/plain Return-path: In-Reply-To: <20110523181723.GA18971@redhat.com> (Mike Snitzer's message of "Mon, 23 May 2011 14:17:24 -0400") Sender: linux-scsi-owner@vger.kernel.org To: Mike Snitzer Cc: "Martin K. Petersen" , device-mapper development , "Alasdair G. Kergon" , linux-scsi@vger.kernel.org List-Id: dm-devel.ids >>>>> "Mike" == Mike Snitzer 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