From: Alasdair G Kergon <agk@redhat.com>
To: Scott Moser <smoser@brickies.net>
Cc: linux-lvm@redhat.com
Subject: Re: [linux-lvm] Why does thinpool take 2*poolmetadatasize space?
Date: Tue, 20 Oct 2020 18:02:52 +0100 [thread overview]
Message-ID: <20201020170252.GA5698@agk-dp.fab.redhat.com> (raw)
In-Reply-To: <CAKxE60zw4MvD58ds-71yQdyxFkrujCm1XHNfbF=yYRqMRHF63w@mail.gmail.com>
On Tue, Oct 20, 2020 at 12:33:41PM -0400, Scott Moser wrote:
> When I create an lvmthinpool with size S and poolmetadatasize P,
> it reduces the available freespace by S+2P. I expected that to
> be S+P. Where did the extra poolmetadatasize get used?
So that you have sufficient disk space to store a second copy of it
if you need to perform any work on the metadata in future.
Recovery operations, for example, create a recovered copy in that
'spare' space then swap to use it leaving the space used by the
original metadata as the new 'spare'.
Alasdair
next prev parent reply other threads:[~2020-10-20 17:02 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-20 16:33 [linux-lvm] Why does thinpool take 2*poolmetadatasize space? Scott Moser
2020-10-20 17:02 ` Alasdair G Kergon [this message]
2020-10-20 18:02 ` Zdenek Kabelac
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