From: Mike Snitzer <snitzer@redhat.com>
To: LVM general discussion and development <linux-lvm@redhat.com>
Subject: Re: [linux-lvm] Powerfailure and snapshot consistency
Date: Mon, 28 Mar 2011 14:34:39 -0400 [thread overview]
Message-ID: <20110328183439.GA27675@redhat.com> (raw)
In-Reply-To: <alpine.LRH.2.00.1103281319240.13964@bmsred.bmsi.com>
On Mon, Mar 28 2011 at 1:24pm -0400,
Stuart D. Gathman <stuart@bmsi.com> wrote:
> On Mon, 28 Mar 2011, Phillip Susi wrote:
>
> >On 3/27/2011 5:55 PM, Stuart D. Gathman wrote:
> >>Don't need help, just trying to understand the event. So from what you
> >>said, the problem probably stems from the RAID1 resync, which could
> >>make one PV "older" than the other.
> >
> >The data is written to the primary mirror first, so this can't happen.
> >Proper use of barriers will prevent this whole scenario, so my guess is
> >that you are using ext3 ( which defaults to nobarrier ) or explicitly
> >mounting ext4 with nobarrier.
>
> Ah, thank you! Yes, I am using ext3 with EL5.5 defaults, and will now learn
> about the barrier option. Seems like a good thing to turn on when "replace
> battery" comes up on the ups.
RHEL5.x's DM doesn't support barriers (nor does MD afaik).
next prev parent reply other threads:[~2011-03-28 18:34 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-03-26 4:24 [linux-lvm] Powerfailure and snapshot consistency Stuart D. Gathman
2011-03-26 4:42 ` Ron Johnson
2011-03-26 4:52 ` Stuart D. Gathman
2011-03-26 5:25 ` Ron Johnson
2011-03-26 5:53 ` hansbkk
2011-03-26 16:07 ` Stuart D. Gathman
2011-03-26 20:30 ` Mike Snitzer
2011-03-27 21:55 ` Stuart D. Gathman
2011-03-28 17:20 ` Phillip Susi
2011-03-28 17:24 ` Stuart D. Gathman
2011-03-28 17:37 ` Phillip Susi
2011-03-28 21:26 ` Stuart D. Gathman
2011-03-28 18:34 ` Mike Snitzer [this message]
2011-03-28 17:26 ` Les Mikesell
2011-03-28 17:54 ` Stuart D. Gathman
2011-03-28 19:43 ` Ron Johnson
2011-03-26 7:49 ` Ray Morris
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