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/
Home Products Support Community News


Re: [Xen-users] RE: Tutorial : Debian, Xen and CLUSTER / GFS Supp ort

To: PAINCHAUD Christophe <cpainchaud@xxxxxxxxxxx>
Subject: Re: [Xen-users] RE: Tutorial : Debian, Xen and CLUSTER / GFS Supp ort
From: Molle Bestefich <molle.bestefich@xxxxxxxxx>
Date: Fri, 16 Dec 2005 12:37:52 +0100
Cc: xen-users@xxxxxxxxxxxxxxxxxxx
Delivery-date: Fri, 16 Dec 2005 11:40:09 +0000
Domainkey-signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=MSS2YBPRFxESwp8LgrC5qo7/7nonlhKVecCN2Wzp30oQQxOzjI7Cgo7TsB3CHXI+v2yb1Bk5OSmoO7VYNHPXSyk6lcqc3BzOnwa92iBT4dYZuH31e1ystzSMB3MPbHrjjmUm2eG2cCWofw/IxKPNNa3GwqQm96t9hbLEiCrxcss=
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <E4D4F968E9F97F45B21B72BDCAD8E1B8EA4197@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx>
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: <E4D4F968E9F97F45B21B72BDCAD8E1B8EA4197@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx>
Sender: xen-users-bounces@xxxxxxxxxxxxxxxxxxx
PAINCHAUD Christophe wrote:
> For my LVM/DM snapshot tests, I have created 4 block devices of 8GB in LVM
> group of 50GB. I am using DM and LVM2 libs and daemon from the Debian Etch
> packages. I wrote a program to write randomly in the 4 block devices (it
> looks like it's write about 20MB/s, I didn't really optimize it.). While
> this program is active, I do a snapshot of the first volume, and copy it on
> a tape device, I destroy snapshot, then do the same with second, third and
> fourth volume. I launched the loop of snapshot/backups many times in day
> without a single problem.

I'm very impressed!

> > I've got an HP ProLiant (x86_64)

> My test were made on a Dell 1750 (32bit) with a Perc 3D/I SCSI card.
> Did you experience any problem?

Yes.  I took one snapshot of a 3GB full 20GB ext3 volume onto a 10GB
snapshot target volume.  After executing the LVM2 snapshot command,
the original 20GB volume was trashed.  Seems like all disk accesses to
the 20GB volume were misaligned by a few kB's or so.  I could see
directories and files, but only because that's cached in RAM. 
Contents of all files were swapped randomly.  Totally trashed.

I wrote a bug report to dm-devel and got no replies.
I wrote a bug report to RedHat (Fedora Core 4, which I was using at
the time) and got no replies.


Xen-users mailing list

<Prev in Thread] Current Thread [Next in Thread>
  • Re: [Xen-users] RE: Tutorial : Debian, Xen and CLUSTER / GFS Supp ort, Molle Bestefich <=