From: Zdenek Kabelac <zdenek.kabelac@gmail.com>
To: LVM general discussion and development <linux-lvm@redhat.com>,
Gionatan Danti <g.danti@assyoma.it>
Cc: Demi Marie Obenour <demi@invisiblethingslab.com>
Subject: Re: [linux-lvm] Running thin_trim before activating a thin pool
Date: Mon, 31 Jan 2022 14:41:06 +0100 [thread overview]
Message-ID: <d768d362-4081-b91b-462c-e70fe40e32ba@gmail.com> (raw)
In-Reply-To: <9c35198501aae82e7a911f5418cfd7f6@assyoma.it>
Dne 31. 01. 22 v 12:02 Gionatan Danti napsal(a):
> Il 2022-01-29 18:45 Demi Marie Obenour ha scritto:
>> Is it possible to configure LVM2 so that it runs thin_trim before it
>> activates a thin pool? Qubes OS currently runs blkdiscard on every thin
>> volume before deleting it, which is slow and unreliable. Would running
>> thin_trim during system startup provide a better alternative?
>
> I think that, if anything, it would be worse: a long discard during boot can
> be problematic, even leading to timeout on starting other services.
> After all, blkdiscard should be faster then something done at higher level.
>
> That said, I seem to remember that deleting a fat volume should automatically
> trim/discard it if issue_discard=1. Is this not true for thin volumes?
'issue_discard' relates only to the internal lvm2 logic when some extents
become free for reuse (so i.e. after 'lvremove/lvreduce/vgremove...'.
However since with thin volumes no physical extents of VG are released (as the
thin volume is releasing chunks from the thin-pool) - there is no discard
issued by lvm.
Regards
Zdenek
_______________________________________________
linux-lvm mailing list
linux-lvm@redhat.com
https://listman.redhat.com/mailman/listinfo/linux-lvm
read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
next prev parent reply other threads:[~2022-01-31 13:41 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-01-29 17:45 [linux-lvm] Running thin_trim before activating a thin pool Demi Marie Obenour
2022-01-31 11:02 ` Gionatan Danti
2022-01-31 13:41 ` Zdenek Kabelac [this message]
2022-01-31 14:12 ` Gionatan Danti
2022-01-31 15:28 ` Demi Marie Obenour
2022-01-31 17:54 ` Gionatan Danti
2022-01-31 19:04 ` Demi Marie Obenour
2022-01-29 18:52 Demi Marie Obenour
2022-01-29 19:42 ` Zdenek Kabelac
2022-01-29 20:09 ` Demi Marie Obenour
2022-01-29 21:40 ` Zdenek Kabelac
2022-01-30 1:20 ` Demi Marie Obenour
2022-01-30 11:18 ` Zdenek Kabelac
2022-01-30 17:30 ` Demi Marie Obenour
2022-01-30 17:56 ` Zdenek Kabelac
2022-01-30 18:01 ` Demi Marie Obenour
2022-01-30 18:42 ` Zdenek Kabelac
2022-01-30 20:22 ` Gionatan Danti
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=d768d362-4081-b91b-462c-e70fe40e32ba@gmail.com \
--to=zdenek.kabelac@gmail.com \
--cc=demi@invisiblethingslab.com \
--cc=g.danti@assyoma.it \
--cc=linux-lvm@redhat.com \
/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).