From: Alasdair G Kergon <agk@redhat.com>
To: Stuart D Gathman <stuart@bmsi.com>
Cc: linux-lvm@redhat.com
Subject: Re: [linux-lvm] Duplicate PV's - how does LVM choose which one to use
Date: Tue, 21 Feb 2012 17:07:43 +0000 [thread overview]
Message-ID: <20120221170743.GC14666@agk-dp.fab.redhat.com> (raw)
In-Reply-To: <4F43CB24.5060901@bmsi.com>
On Tue, Feb 21, 2012 at 11:49:40AM -0500, Stuart D Gathman wrote:
> But if they are different paths, incrementing seqno won't hurt, both
> paths will see the change. And if it is a mirror that failed to start,
> then the chosen leg is now distinguishable. Is there a problem with
> incrementing seqno an extra time at startup when multipath is the normal
> situation?
If you update some PV-level indicator and only one path sees the update, then
that's exactly a case where you must use neither until the sysadmin decides
which was the right one to use. And the other case - multipath - well again,
why didn't your multipath software start up and take control?
Alasdair
prev parent reply other threads:[~2012-02-21 17:07 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-02-21 8:40 [linux-lvm] Duplicate PV's - how does LVM choose which one to use Danilo Godec
2012-02-21 12:09 ` Alasdair G Kergon
2012-02-21 16:35 ` Ray Morris
2012-02-21 16:43 ` Alasdair G Kergon
2012-02-21 16:49 ` Stuart D Gathman
2012-02-21 17:07 ` Alasdair G Kergon [this message]
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