From mboxrd@z Thu Jan  1 00:00:00 1970
From: Samuel Thibault <samuel.thibault@eu.citrix.com>
Subject: Re: IO caching on xen?
Date: Tue, 15 Jul 2008 12:30:53 +0100
Message-ID: <20080715113053.GH4529@implementation.uk.xensource.com>
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To: marian klein <klein.marian@gmail.com>
Cc: xen-devel@lists.xensource.com, xen-discuss@opensolaris.org
List-Id: xen-devel@lists.xenproject.org

Hello,

marian klein, le Tue 15 Jul 2008 11:22:05 +0000, a =E9crit :
> I am worried that the xen (or any other VM) with zvol device from ZFS
> (or any other file system.) may remove the benefits of ZFS,
>  because the guest OS can write something to disk but the xen itself
> can do some buffering
> or lazy writing and it may delay to write to ZFS backend.

Xen doesn't do any kind of buffering or lazy writing.  It provides
barriers to the guest, to ensure any needed coherency.

Samuel