From: "Theodore Y. Ts'o" <tytso@mit.edu>
To: Mike Snitzer <snitzer@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>,
Huaisheng Ye <yehs2007@zoho.com>, Jan Kara <jack@suse.cz>,
Dave Chinner <david@fromorbit.com>,
"linux-nvdimm@lists.01.org" <linux-nvdimm@lists.01.org>,
"dm-devel@redhat.com" <dm-devel@redhat.com>,
Mikulas Patocka <mpatocka@redhat.com>,
"linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>,
chengnt <chengnt@lenovo.com>, yehs1 <yehs1@lenovo.com>,
colyli <colyli@suse.de>
Subject: Re: Snapshot target and DAX-capable devices
Date: Wed, 12 Dec 2018 16:15:47 -0500 [thread overview]
Message-ID: <20181212211547.GA24926@thunk.org> (raw)
In-Reply-To: <20181212175047.GA24962@redhat.com>
On Wed, Dec 12, 2018 at 12:50:47PM -0500, Mike Snitzer wrote:
> On Wed, Dec 12 2018 at 11:12am -0500,
> Christoph Hellwig <hch@infradead.org> wrote:
>
> > Does it really make sense to enhance dm-snapshot? I thought all serious
> > users of snapshots had moved on to dm-thinp?
>
> There are cases where dm-snapshot is still useful for people. But those
> are very niche users. I'm not opposed to others proposing enhancements
> for dm-snapshot in general but it is definitely not a priority (Google's
> dm-bow is an example of a case where dm-snapshot may get extended to
> fulfill google's needs).
I would expect that dm-snapshot will be used quite a lot for
short-lived snapshots (that only live during a database backup or an
fsck run). I would hardly call that a "niche use case". One other
major advantage that dm-snapshot has is that you can take a snapshot
for any LVM volume. For dm-thinp you have migrate your storage to a
thinp pool, and that adds a fair amount of friction to users migrating
to dm-thinp.
- Ted
next prev parent reply other threads:[~2018-12-12 21:15 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-27 16:07 Snapshot target and DAX-capable devices Jan Kara
2018-08-27 16:43 ` Kani, Toshi
2018-08-28 7:50 ` Jan Kara
2018-08-28 17:56 ` Mike Snitzer
2018-08-28 22:38 ` Kani, Toshi
2018-08-30 9:30 ` Jan Kara
2018-08-30 18:49 ` Mike Snitzer
2018-08-30 19:32 ` Jeff Moyer
2018-08-30 19:47 ` Mikulas Patocka
2018-08-30 19:53 ` Jeff Moyer
2018-08-30 23:38 ` Dave Chinner
2018-08-31 9:42 ` Jan Kara
2018-09-05 1:25 ` Dave Chinner
2018-12-12 16:11 ` Huaisheng Ye
2018-12-12 16:12 ` Christoph Hellwig
2018-12-12 17:50 ` Mike Snitzer
2018-12-12 19:49 ` Kani, Toshi
2018-12-12 21:15 ` Theodore Y. Ts'o [this message]
2018-12-12 22:43 ` Mike Snitzer
2018-12-14 4:11 ` [dm-devel] " Theodore Y. Ts'o
2018-12-14 8:24 ` [External] " Huaisheng HS1 Ye
2018-12-18 19:49 ` Mike Snitzer
2018-08-30 19:44 ` Mikulas Patocka
2018-08-31 10:01 ` Jan Kara
2018-08-30 22:55 ` Dave Chinner
2018-08-31 9:54 ` Jan Kara
2018-08-30 19:17 ` [dm-devel] " Jeff Moyer
2018-08-31 9:14 ` Jan Kara
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