From mboxrd@z Thu Jan  1 00:00:00 1970
From: Matthias Ferdinand <bcache@mfedv.net>
Subject: Re: =?utf-8?B?562U5aSNOiBhIHN0cmFuZw==?= =?utf-8?Q?e?= bcache0 100%
 busy with no IO rw and no cpu consumption
Date: Sun, 14 May 2017 15:53:49 +0200
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On Sun, May 14, 2017 at 05:33:12PM +0800, 朱菁 wrote:
> Hi:
> 	Thx for your reply.
> 	/dev/sdb on esxi-node  equal bcache0 on stor-node.

sorry, it just looked too easy :-)

I have also seen suspiciously high iostat values on bcache devices,
where extreme values of "wkB/s" go together with high "avgrq-sz"
(probably a derived value), but never on two consecutive measurements,
always several days in between. But "%util" always looked ok.

Since iostat is just reading /proc/diskstat, I would rather suspect some
(bcache related) bug there.

Sometimes I also see funny numbers in writeback_rate_debug, e.g.
increasing "dirty" values like this: 
   2.8M .. 2.9M .. 2.10M .. 3.0M

Matthias