WARNING - OLD ARCHIVES

This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
   
 
 
Xen 
 
Home Products Support Community News
 
   
 

xen-devel

[Xen-devel] inconsistent metadata of vhd file while live migration

To: xen-devel@xxxxxxxxxxxxxxxxxxx
Subject: [Xen-devel] inconsistent metadata of vhd file while live migration
From: alice wan <wanjia19870902@xxxxxxxxx>
Date: Sun, 13 Feb 2011 23:45:36 +0800
Delivery-date: Sun, 13 Feb 2011 07:46:37 -0800
Dkim-signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:date:message-id:subject:from:to :content-type; bh=lHs/YEuX3kAPNvB/gddvvkFEf/YZnDc6qO0+NCmZy68=; b=D2OlGjxle9ShsDa03iGyj/bijv1yl8nsz+xZZTFqEv1rKwpBVZiJvc1QEXp8RbF5ya pksgPGlPOGwRqF51FuJ7CuEH8EVCjfkSnAoTG5BYlCqzj2XSQaxasXxiN8irK4X0A5te e72cqr5JgDeuTX7fnJwfqc4/5Z36H7f400XNg=
Domainkey-signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:date:message-id:subject:from:to:content-type; b=nXCtsOwt3K+a2iJBzMY7FPIGsvlenavNAhybm3g1olZ3BxPXP1R/S9aP5P3MkFIWg2 vH4eCS05lTJCtv2/XmJ27BRyog2l/1AWe8ufKE0wnkRvPx0Ppw6hI2T+/oY4JZ2MVeof ycpoBvq64EZHFX2K0bJPQo3XaYy4kPP9ESplE=
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
List-help: <mailto:xen-devel-request@lists.xensource.com?subject=help>
List-id: Xen developer discussion <xen-devel.lists.xensource.com>
List-post: <mailto:xen-devel@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
hi all,
 
i have some doubt about live migration which may cause inconsistent metadata of vhd file between two tapdisk2 process.
 
given that vm migrates from host A to host B, which image is vhd file.
 
in host B, it first creates devices including starting tapdisk2 process, at this time, tapdisk2 will read some metadata of vhd file. then, it xc_restore
 
in host A, before it start last iteration(stop-and-copy phase), while xc_save's going, vhd file has been changed including metadata. So, in hostB tapdisk2 process doesn't read the
 
newest metadata of vhd file.
 
for tapdisk2, when it starts, it will read footer, header, bat of vhd file. especially bat structure, if it's inconsistent, it'll cause problem.
 
Maybe my doubt isn't a real problem, however, i hope someone to figure it out for me. thanks in advance.
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel