linux-btrfs.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Hans van Kranenburg <hans.van.kranenburg@mendix.com>
To: Martin Raiber <martin@urbackup.org>,
	"linux-btrfs@vger.kernel.org" <linux-btrfs@vger.kernel.org>
Subject: Re: Multiple btrfs-cleaner threads per volume
Date: Thu, 2 Nov 2017 16:10:35 +0100	[thread overview]
Message-ID: <75dfd17b-3f3a-dc22-e069-d68faa33eb8e@mendix.com> (raw)
In-Reply-To: <0102015f7d418aa6-af3c2ae7-27b0-47d0-a4bb-173f55304bb9-000000@eu-west-1.amazonses.com>

Hi Martin,

On 11/02/2017 04:02 PM, Martin Raiber wrote:
> 
> snapshot cleanup is a little slow in my case (50TB volume). Would it
> help to have multiple btrfs-cleaner threads? The block layer underneath
> would have higher throughput with more simultaneous read/write requests.

Just curious:
* How many subvolumes/snapshots are you removing, and what's the
complexity level (like, how many other subvolumes/snapshots reference
the same data extents?)
* Do you see a lot of cpu usage, or mainly a lot of disk I/O? If it's
disk IO, is it mainly random read IO, or is it a lot of write traffic?
* What mount options are you running with (from /proc/mounts)?

-- 
Hans van Kranenburg

  parent reply	other threads:[~2017-11-02 15:10 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-11-02 15:02 Multiple btrfs-cleaner threads per volume Martin Raiber
2017-11-02 15:07 ` Austin S. Hemmelgarn
2017-11-02 15:10 ` Hans van Kranenburg [this message]
2017-11-02 15:26   ` Martin Raiber
2017-11-02 16:56     ` Hans van Kranenburg

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=75dfd17b-3f3a-dc22-e069-d68faa33eb8e@mendix.com \
    --to=hans.van.kranenburg@mendix.com \
    --cc=linux-btrfs@vger.kernel.org \
    --cc=martin@urbackup.org \
    /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).