qemu-devel.nongnu.org archive mirror
 help / color / mirror / Atom feed
From: Yaowei Bai <baiyaowei@cmss.chinamobile.com>
To: pbonzini@redhat.com, fam@euphon.net, dillaman@redhat.com,
	kwolf@redhat.com, mreitz@redhat.com
Cc: baiyaowei@cmss.chinamobile.com, qemu-devel@nongnu.org,
	qemu-block@nongnu.org
Subject: [Qemu-devel] COMPARE_AND_WRITE support for rbd driver
Date: Thu, 19 Sep 2019 13:36:23 +0800	[thread overview]
Message-ID: <20190919053623.GA19956@byw> (raw)

baiyaowei@cmss.chinamobile.com 
Bcc: 
Subject: COMPARE_AND_WRITE support for rbd driver
Reply-To: baiyaowei@cmss.chinamobile.com

Hey guys,

I noticed that COMPARE_AND_WRITE had been supported by CEPH/librbd since
v12.1.1. And in my company, we use this COMPARE_AND_WRITE support in
CEPH with the ISCSI protocol. More precisely, we use tgt and CEPH with this
COMPARE_AND_WRITE support as the SCSI target and export it to the remote
hosts. And then VMs on remote hosts can use these SCSI targets through ISCSI
initiator support in QEMU directly or as local SCSI disks. But unfortunately,
there're some issues with this tgt case. So i think maybe we could also add this
COMPARE_AND_WRITE support into the rbd driver in QEMU so we can leave the
ISCSI/tgt alone and use this COMPARE_AND_WRITE support with the
scsi-disk <--> virtio-scsi <--> rbd driver path. This can also apply to
the WRITESAME support in CEPH/librbd.

So is it suitable for doing this? I want to hear suggestions from you
genius guys. Appreciate it.




             reply	other threads:[~2019-09-19  5:38 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-09-19  5:36 Yaowei Bai [this message]
2019-09-20 11:22 ` COMPARE_AND_WRITE support for rbd driver Paolo Bonzini
2019-09-20 15:26   ` Yaowei Bai

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20190919053623.GA19956@byw \
    --to=baiyaowei@cmss.chinamobile.com \
    --cc=dillaman@redhat.com \
    --cc=fam@euphon.net \
    --cc=kwolf@redhat.com \
    --cc=mreitz@redhat.com \
    --cc=pbonzini@redhat.com \
    --cc=qemu-block@nongnu.org \
    --cc=qemu-devel@nongnu.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).