From: Christian Rohmann <crohmann@netcologne.de>
To: linux-btrfs@vger.kernel.org
Subject: btrfs-progs 4.4 re-balance of RAID6 is very slow / limited to one cpu core?
Date: Fri, 22 Jan 2016 14:38:11 +0100 [thread overview]
Message-ID: <56A230C3.3080100@netcologne.de> (raw)
Hello btrfs-folks,
I am currently doing a big "btrfs balance" to extend a 8 drive RAID6 to
12 drives using
"btrfs balance start -dstripes 1..11 -mstripes 1..11"
With kernel 4.4 and btrfs progs 4.4 it's running fine for a few days now
and the new disks are slowing getting more and more extents.
But somehow the process is VERY slow (3% in 3 days) and there is almost
no additional disk utilization.
The process doing the balance is doing 100% cpu (one core) so apparently
the whole thing is very much single threaded and therefore CPU-bound in
this case.
Is this a known issue or is there anything I can do to speed this up? I
mean the disks have plenty of iops left to work with and the box has
many more CPU cores idling away.
Regards
Christian
next reply other threads:[~2016-01-22 13:38 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-01-22 13:38 Christian Rohmann [this message]
2016-01-22 14:51 ` btrfs-progs 4.4 re-balance of RAID6 is very slow / limited to one cpu core? Duncan
2016-01-24 2:30 ` Henk Slager
2016-01-25 11:34 ` Christian Rohmann
2016-01-25 22:13 ` Chris Murphy
[not found] ` <CAKZK7uxdX9UBPOKButtPjqBOdVUfHdRTimP+W34fkz1h9P+wHg@mail.gmail.com>
2016-01-26 0:44 ` Fwd: " Justin Brown
2016-01-26 5:17 ` Chris Murphy
2016-01-26 6:14 ` Chris Murphy
2016-01-26 8:54 ` Christian Rohmann
2016-01-26 19:26 ` Chris Murphy
2016-01-26 19:27 ` Chris Murphy
2016-01-26 19:57 ` Austin S. Hemmelgarn
2016-01-26 20:20 ` Chris Murphy
2016-01-27 8:48 ` Christian Rohmann
2016-01-27 16:34 ` Austin S. Hemmelgarn
2016-01-27 20:58 ` bbrendon
2016-01-27 21:53 ` Chris Murphy
2016-01-28 12:27 ` Austin S. Hemmelgarn
2016-02-01 14:10 ` Christian Rohmann
2016-02-01 20:52 ` Chris Murphy
2016-02-09 13:48 ` Christian Rohmann
2016-02-09 16:46 ` Marc MERLIN
2016-02-09 21:46 ` Chris Murphy
2016-02-10 2:23 ` Chris Murphy
2016-02-10 2:36 ` Chris Murphy
2016-02-10 13:19 ` Christian Rohmann
2016-02-10 19:16 ` Chris Murphy
2016-02-10 19:38 ` Chris Murphy
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