From: Tobias <tracer@robotech.de>
To: sander@humilis.net
Cc: linux-btrfs@vger.kernel.org
Subject: Re: Extreme slowdown
Date: Fri, 16 Dec 2011 18:45:46 +0100 [thread overview]
Message-ID: <4EEB83CA.5050904@robotech.de> (raw)
In-Reply-To: <20111216091959.GA4051@attic.humilis.net>
Am 16.12.2011 10:19, schrieb Sander:
> Tobias wrote (ao):
>>>>> On Fri, Dec 16, 2011 at 1:49 AM, Tobias<tracer@robotech.de> wrote:
>>>>>> My BTRFS-FS ist getting really slow. Reading is ok, writing is
>>>>>> slow and deleting is horrible slow.
>>>>>>
>>>>>> There are many files and many links on the FS.
> Do you happen to have (many) snapshots? Are btrfs kernel threads using a
> lot of cpu?
>
No Snapshots at all. Only compress-force=lzo, nothing else special.
The CPU is almost idle, IOwait is at 100%; looks likes the discs are
accessing many small blocks. (seeking like hell...)
Output from iostat (average each over 120 seconds)
Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s
avgrq-sz avgqu-sz await r_await w_await svctm %util
sdb 0.00 0.42 195.31 190.44 781.23 1657.90
12.65 64.91 168.90 3.42 338.60 2.51 96.64
sdb 0.00 0.50 75.00 336.57 300.00 2028.60
11.32 105.41 255.83 3.16 312.14 2.24 92.38
sdb 0.00 0.62 72.03 441.72 288.11 2164.88
9.55 116.39 226.27 4.20 262.48 1.89 97.29
sdb 0.00 0.20 1.07 468.74 4.26 2604.99
11.11 145.07 308.91 581.30 308.29 2.13 100.00
sdb 0.00 0.00 20.00 326.97 80.00 2114.03
12.65 38.56 111.41 58.02 114.67 2.83 98.28
sdb 0.00 0.00 5.02 563.35 20.08 3102.45
10.99 137.71 242.26 6.44 244.36 1.70 96.62
Tobias
prev parent reply other threads:[~2011-12-16 17:45 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-12-15 18:49 Extreme slowdown Tobias
2011-12-16 2:09 ` Liu Bo
2011-12-16 8:51 ` Tobias
2011-12-16 9:11 ` Hugo Mills
2011-12-16 2:19 ` Fajar A. Nugraha
2011-12-16 3:44 ` Chester
2011-12-16 4:15 ` Shyam Prasad N
2011-12-16 9:09 ` Tobias
2011-12-16 9:19 ` Sander
2011-12-16 17:45 ` Tobias [this message]
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