From: Zdenek Kabelac <zkabelac@redhat.com>
To: LVM general discussion and development <linux-lvm@redhat.com>,
Scott Moser <smoser@brickies.net>
Subject: Re: [linux-lvm] Why does thinpool take 2*poolmetadatasize space?
Date: Tue, 20 Oct 2020 20:02:04 +0200 [thread overview]
Message-ID: <69aeb37e-ee16-6bdb-0ae3-456b83c99289@redhat.com> (raw)
In-Reply-To: <CAKxE60zw4MvD58ds-71yQdyxFkrujCm1XHNfbF=yYRqMRHF63w@mail.gmail.com>
Dne 20. 10. 20 v 18:33 Scott Moser napsal(a):
> 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?
>
> See below for example.
> before lvcreate we had 255868 free, after we had 254588.
> The difference is 1280. (1024 + 2*128).
>
lvm2 preallocated hidden _pmspare volume which has the size of
biggest metadata LV in a VG.
Such LV is used for automated 'lvconvert --repair'.
If you don't want this LV to be created you can add
--poolmetadataspare y|n
but in this case you are fully in your own to figure out,
where to take the space for repaired metadata.
You can also at any time lvremove _pmspare LV if necessary.
Regards
Zdenek
prev parent reply other threads:[~2020-10-20 18:02 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
2020-10-20 18:02 ` Zdenek Kabelac [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=69aeb37e-ee16-6bdb-0ae3-456b83c99289@redhat.com \
--to=zkabelac@redhat.com \
--cc=linux-lvm@redhat.com \
--cc=smoser@brickies.net \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).