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] xvda vs lvm

To: xen-users@xxxxxxxxxxxxxxxxxxx
Subject: Re: [Xen-users] xvda vs lvm
From: Mark Williamson <mark.williamson@xxxxxxxxxxxx>
Date: Wed, 25 Apr 2007 03:40:40 +0100
Cc: tarjei <tarjei@xxxxx>
Delivery-date: Tue, 24 Apr 2007 19:40:04 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxx
In-reply-to: <46290023.7010400@xxxxx>
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: <46290023.7010400@xxxxx>
Sender: xen-users-bounces@xxxxxxxxxxxxxxxxxxx
User-agent: KMail/1.9.6
> Hi, I'm just wondering if there are any speed or stability differences
> between running a system directly of a LVM partition versus a xvd
> partition?
>

I'm a little confused about what you're asking, so I'll explain a few things 
and hopefully it'll help some.  Please ask again if I'm not answering the 
questions you wanted.

> Basicly:
> disk = [ 'phy:/dev/LVM/root,xvda,w', ]

This exports /dev/LVM/root as the whole disk device /dev/xvda in the guest.

> disk= [ 'phy:LVM/root,hda1,w',]

This exports /dev/LVM/root (as before) as the partition /dev/hda1 in the 
guest.

So, whether or not you include /dev in the device path, you're still exporting 
the same device.

As to whether to export a whole device or a partition...

Exporting as a single partition (e.g. /dev/hda1 in your example) has the 
advantage that /dev/LVM/root will be directly mountable in dom0 because it 
will not have been partitioned by the guest.  The guest won't be allowed to 
repartition /dev/hda, it'll be stuck with one partition there.

Exporting as a whole device gives the guest flexibility to partition its VBD 
as it sees fit but means it's slightly less convenient to mount /dev/LVM/root 
in dom0 (but there are tools to read the partition and make this easy for 
you).

I usually go for the latter approach, but it doesn't matter in terms of speed 
and stability.  It's really quest a question of administration convenience 
and how you want things to look like the guest.

Cheers,
Mark

-- 
Dave: Just a question. What use is a unicyle with no seat?  And no pedals!
Mark: To answer a question with a question: What use is a skateboard?
Dave: Skateboards have wheels.
Mark: My wheel has a wheel!

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

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