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From: Ilya Dryomov <idryomov@gmail.com>
To: KAMEI Hitoshi <hitoshi.kamei.xm@hitachi.com>
Cc: Sage Weil <sage@redhat.com>, Alex Elder <elder@kernel.org>,
	Ceph Development <ceph-devel@vger.kernel.org>,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH 0/2] rbd: thick-provision image support
Date: Tue, 20 Mar 2018 15:06:49 +0100	[thread overview]
Message-ID: <CAOi1vP8qz9GeP0Beypq1N8XFwzkPieEE1Qf6gJafPnngjNG86g@mail.gmail.com> (raw)
In-Reply-To: <5AAFA661.60103@hitachi.com>

On Mon, Mar 19, 2018 at 1:00 PM, KAMEI Hitoshi
<hitoshi.kamei.xm@hitachi.com> wrote:
> This patch series adds the thick-provision image support to
> /drivers/block/rbd.c relating to https://github.com/ceph/ceph/pull/18317.
> The rbd will not issue the discard operation to thick-provision
> images, if applied.
>
> The rbd should not discard any allocated blocks of thick-provision
> image to ensure writing data to rbd images. So this patch
> prevents from discarding allocated blocks on thick-provision
> image.
>
> This patch series creates sysfs file to manipulate thick-provision
> status. If users write "1" to /sys/bus/rbd/devices/<dev-id>/thick,
> then the image is changed to thick-provision image. And if users
> write "0" to it, then the image is changed to thin-provision
> image. I will add the code changing status for the rbd map command.

Hi Hitoshi,

I think it should be a map time option -- e.g. rbd map -o thick.
I don't see any reason for allowing tweaking this setting on a mapped
image.

I looked through https://github.com/ceph/ceph/pull/18317 and I don't
see an equivalent functionality there.  rbd_discard_on_zeroed_write_same
set to false makes the actual zeroes go on the wire, but I don't see
anything for ignoring discard requests.  Can you point me at that?

Thanks,

                Ilya

  reply	other threads:[~2018-03-20 14:06 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-03-19 12:00 [PATCH 0/2] rbd: thick-provision image support KAMEI Hitoshi
2018-03-20 14:06 ` Ilya Dryomov [this message]
2018-03-20 22:31   ` Jason Dillaman
2018-03-22 11:59     ` 亀井仁志 / KAMEI，HITOSHI
2018-03-22 11:58   ` 亀井仁志 / KAMEI，HITOSHI

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