From: Paolo Bonzini <pbonzini@redhat.com>
To: Orit Wasserman <owasserm@redhat.com>
Cc: "kwolf@redhat.com" <kwolf@redhat.com>,
"famz@redhat.com" <famz@redhat.com>, Peter Lieven <pl@kamp.de>,
"qemu-devel@nongnu.org" <qemu-devel@nongnu.org>,
"stefanha@redhat.com" <stefanha@redhat.com>
Subject: Re: [Qemu-devel] [PATCHv2] block: add native support for NFS
Date: Wed, 18 Dec 2013 11:38:35 +0100 [thread overview]
Message-ID: <52B17B2B.1020103@redhat.com> (raw)
In-Reply-To: <52B177E1.6060802@redhat.com>
Il 18/12/2013 11:24, Orit Wasserman ha scritto:
>>>
>>> For live migration we need the sync option (async ignores O_SYNC and
>>> O_DIRECT sadly),
>>> will it be supported? or will it be the default?
>>
>> Since this is bypassing the client kernel FS I/O layer question around
>> support of things like O_SYNC/O_DIRECT are not applicable.
>>
>
> so no live migration support?
No, live migration just works.
O_SYNC is not used anymore in QEMU, we just issue a flush after every write.
And all protocol drivers except files/block devices _always_ bypass the
kernel page cache (libiscsi, NBD, ceph, and now libnfs) so they are
always behaving as if they had O_DIRECT. For these protocols,
cache=writeback and cache=none are entirely the same.
Paolo
next prev parent reply other threads:[~2013-12-18 10:39 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-12-17 9:15 [Qemu-devel] [PATCHv2] block: add native support for NFS Peter Lieven
2013-12-17 16:47 ` Stefan Hajnoczi
2013-12-17 17:03 ` Peter Lieven
2013-12-17 17:13 ` ronnie sahlberg
2013-12-17 22:36 ` Peter Lieven
2013-12-17 22:44 ` Eric Blake
2013-12-17 22:51 ` ronnie sahlberg
2013-12-17 22:56 ` Peter Lieven
2013-12-17 17:28 ` ronnie sahlberg
2013-12-17 23:00 ` Peter Lieven
2013-12-20 9:48 ` Peter Lieven
2013-12-20 12:19 ` Stefan Hajnoczi
2013-12-20 12:53 ` Peter Lieven
2013-12-20 13:57 ` Stefan Hajnoczi
2013-12-20 14:07 ` Peter Lieven
2013-12-20 14:38 ` Stefan Hajnoczi
2013-12-20 14:43 ` Peter Lieven
2013-12-20 15:03 ` ronnie sahlberg
2013-12-20 15:30 ` Stefan Hajnoczi
2013-12-20 15:49 ` Peter Lieven
2013-12-20 15:54 ` Stefan Hajnoczi
2013-12-20 15:57 ` Peter Lieven
2013-12-20 16:27 ` Stefan Hajnoczi
2014-01-03 10:35 ` Peter Lieven
2013-12-17 16:53 ` ronnie sahlberg
2013-12-17 22:57 ` Peter Lieven
2013-12-17 17:32 ` Daniel P. Berrange
2013-12-17 23:03 ` Peter Lieven
2013-12-18 9:30 ` Daniel P. Berrange
2013-12-18 10:00 ` Orit Wasserman
2013-12-18 10:18 ` Daniel P. Berrange
2013-12-18 10:24 ` Orit Wasserman
2013-12-18 10:38 ` Paolo Bonzini [this message]
2013-12-18 17:21 ` Peter Lieven
2013-12-19 14:31 ` Paolo Bonzini
2013-12-18 11:11 ` Peter Lieven
2013-12-18 11:23 ` Orit Wasserman
2013-12-18 14:42 ` ronnie sahlberg
2013-12-18 16:59 ` Peter Lieven
2013-12-18 17:33 ` ronnie sahlberg
2013-12-18 17:42 ` Peter Lieven
2013-12-18 17:50 ` ronnie sahlberg
2013-12-18 17:55 ` Peter Lieven
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=52B17B2B.1020103@redhat.com \
--to=pbonzini@redhat.com \
--cc=famz@redhat.com \
--cc=kwolf@redhat.com \
--cc=owasserm@redhat.com \
--cc=pl@kamp.de \
--cc=qemu-devel@nongnu.org \
--cc=stefanha@redhat.com \
/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).