From: Joe Thornber <thornber@redhat.com>
To: Johannes Bauer <dfnsonfsduifb@gmx.de>,
device-mapper development <dm-devel@redhat.com>
Subject: Re: dm-cache coherence issue
Date: Mon, 26 Jun 2017 16:58:08 +0100 [thread overview]
Message-ID: <20170626155808.GC20683@nim> (raw)
In-Reply-To: <20170626113341.GA20683@nim>
On Mon, Jun 26, 2017 at 12:33:42PM +0100, Joe Thornber wrote:
> On Sat, Jun 24, 2017 at 03:56:54PM +0200, Johannes Bauer wrote:
> > So I seem to have a very basic misunderstanding of what the cleaner
> > policy/dirty pages mean. Is there a way to force the cache to flush
> > entirely? Apparently, "dmsetup wait" and/or "sync" don't do the job.
>
> I'll try and reproduce your scenario and get back to you.
Here's a similar scenario that I've added to the dm test suite:
https://github.com/jthornber/device-mapper-test-suite/commit/457e889b0c4d510609c0d7464af07f2ebee20768
It goes through all the steps you need to use to decommission a cache
with dirty blocks. Namely:
- switch to writethrough mode (so new io can't create new dirty blocks)
- switch to the cleaner policy
- wait for clean
- remove the cache device before accessing the origin directly
I've run it with a recent kernel, and one from about a year ago and it
passes fine.
- Joe
next prev parent reply other threads:[~2017-06-26 15:58 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-06-24 13:56 dm-cache coherence issue Johannes Bauer
2017-06-24 18:21 ` Johannes Bauer
2017-06-26 11:33 ` Joe Thornber
2017-06-26 15:58 ` Joe Thornber [this message]
2017-06-26 19:08 ` Johannes Bauer
2017-06-26 19:56 ` Mike Snitzer
2017-06-26 20:36 ` Johannes Bauer
2017-06-26 21:34 ` Mike Snitzer
2017-06-27 9:44 ` Joe Thornber
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