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-users

Re: [Xen-users] Domain-0 freezes when mounting a cloned domU with dd

To: xen-users@xxxxxxxxxxxxxxxxxxx
Subject: Re: [Xen-users] Domain-0 freezes when mounting a cloned domU with dd
From: Franck ELIE <Franck.Elie@xxxxxxxxxxxxxxx>
Date: Mon, 20 Aug 2007 17:24:35 +0200
Delivery-date: Mon, 20 Aug 2007 08:25:33 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxx
In-reply-to: <46C9624A.1060503@xxxxxxxxxxxxxxx>
List-help: <mailto:xen-users-request@lists.xensource.com?subject=help>
List-id: Xen user discussion <xen-users.lists.xensource.com>
List-post: <mailto:xen-users@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-users>, <mailto:xen-users-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-users>, <mailto:xen-users-request@lists.xensource.com?subject=unsubscribe>
References: <46C9624A.1060503@xxxxxxxxxxxxxxx>
Sender: xen-users-bounces@xxxxxxxxxxxxxxxxxxx
User-agent: Thunderbird 2.0.0.6 (Windows/20070728)
Franck ELIE a écrit :
Hi

When cloning à domU with 'dd' command (after a domU shutdown), it seems to be very important to perform a 'fsck' on cloned partitions before to mount because if we don't, it freezes Domain-0 and next dom-U.

Just before the kernel froze, logs are full of such message :
kernel: >>ext3_orp>ext3_orph>ext3_orph>ext3_orph>ext3_orpha>ext3_orp>ext3_orpha>ext3_or>ext3_or>ext3_orph>e xt3_orp>ext3_orp>ext3_orph>ext3_or>ext3_orpha>ext3_or>ext3_orp>ext3_or>ext3_orp>ext3_orph>ext3_orpha>ext3_or>ext3_orp>ext3_orp>ext3_ or>ext3_orphan>ext3_orphan_>ext3_orpha>ext3_orp>ext3_orp>ext3_orph>ext3_orphan>ext3_orp>ext3_orp>ext3_orph> ....

Note that when performing a fdisk on such partitions I obtain this output :
# fsck.ext3 /dev/mapper/CMS1
e2fsck 1.40-WIP (14-Nov-2006)
/dev/mapper/CMS1: recovering journal
Truncating orphaned inode 32474 (uid=101, gid=104, mode=0140777, size=0)
/dev/mapper/CMS1: clean, 37928/221312 files, 250275/441779 blocks

By the way, fsck on the template domU seems to be OK.

So, here are my questions :
- Do you know why is it necessary to perform fsck ? Should I use specific options with dd to avoid this effect on the cloned FS ? - Concerning the kernel freeze (that seems not to be specific to my distrib or xen), is it a kernel bug ?

Regards

 Franck

P.S.: xen 3.03, kernel 2.6.18-4-xen-686, Debian Etch, 1 domU per LUN of 2Go, no LVM


Here are the result of tests I just performed to understand what 's wrong :
- there is a MD5 difference between the sum computed from LUN of the domU storage and the image file generated with 'dd' WHEN the backup is performed just after the domU shutdown (less than 3min).
- domain-0 have enough memory (8Go) to copy the domU (2Go)

So, my FS trouble would to be related with a partial copy of domU that seems to be performed with 'dd' before before the end of the memory flush away to disk domU.

So do you know how to perform the memory flush related to a domU in order to backup the disk correctly ?

Any suggestion would be appreciate

Regards

 Franck



_______________________________________________
Xen-users mailing list
Xen-users@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-users

<Prev in Thread] Current Thread [Next in Thread>