From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jes Sorensen Subject: Re: raid1 - mismatches after resuming interrupted recovery Date: Fri, 30 Oct 2015 14:07:23 -0400 Message-ID: References: <559AAAAA.2030904@stratus.com> <5633A172.3020804@stratus.com> Mime-Version: 1.0 Content-Type: text/plain Return-path: In-Reply-To: <5633A172.3020804@stratus.com> (Nate Dailey's message of "Fri, 30 Oct 2015 12:57:22 -0400") Sender: linux-raid-owner@vger.kernel.org To: Nate Dailey Cc: NeilBrown , linux-raid@vger.kernel.org List-Id: linux-raid.ids Nate Dailey writes: > This is the the same as "ignore recovery_offset if bitmap exists", > describing how I hit the problem (before attempting to put a patch > together to fix it). Thanks for the clarification Nate, I thought it was two different issues. Clearly my grey hair is eating away at my brain. Neil please do your best to ignore me :) Jes > On 10/30/2015 11:58 AM, Jes Sorensen wrote: >> Nate Dailey writes: >>> I've found that if I interrupt a recovery by removing the target >>> device, do IO before the recovery checkpoint, then re-add the device >>> and let the recovery complete, the mismatch_cnt is non-zero after >>> doing a check. >> Neil, >> >> While I am on the nagging path, here is another one. >> >> Jes >> >>> Here's exactly what I'm doing: >>> >>> - create a 5 GB raid1 with internal bitmap >>> >>> - do a check, verify zero mismatch_cnt >>> >>> - remove one member device >>> >>> - dd 256MB with 2GB seek >>> >>> - lower sync_speed_min/max to 500 >>> >>> - re-add removed device >>> >>> - wait 15 sec >>> >>> - remove the same member device again >>> >>> - dd 1MB with 1 GB seek >>> >>> - restore sync_speed_min/max to system defaults >>> >>> - re-add removed device >>> >>> - when recovery competes, do another check >>> >>> At this point the mismatch_cnt is non-zero. >>> >>> >>> I originally hit this on RHEL 7.1, but tested 4.1.1 from kernel.org >>> and it happens there too. >>> >>> I'm out of my league in terms of trying to fix this, but would be >>> happy to test a fix. I wonder if it's really necessary to resume a >>> bitmap recovery from the checkpoint? Wouldn't the bitmap always >>> reflect what needs to be copied? >>> >>> Nate >>> >>> -- >>> To unsubscribe from this list: send the line "unsubscribe linux-raid" in >>> the body of a message to majordomo@vger.kernel.org >>> More majordomo info at http://vger.kernel.org/majordomo-info.html