Re: [Xen-users] Best practice to backup dom0 and all domU's

[Andy Smith <andy@xxxxxxxxxxxxxx>]

Hi Rudi,

On Tue, Mar 25, 2008 at 02:33:04PM +0200, Rudi Ahlers wrote:
> on a dual Xeon (4 cores) with 16GB RAM, you could have 15 / 30
> VPS' per physical server. So, you suggest have a iSCSI server, and
> back that up, which means you need 3 physical servers to host the
> same 20 VPS' - which doesn't make sense.

The dom0 could be the iSCSI server, so in fact all you need is
somewhere else to back up to, which you need anyway.

This topic comes up all the time on this list and a lot of people
seem to be of the frame of mind that backup should be something that
Xen should provide.  Well, it is more complicated than that so I
think it is right that Xen does not attempt to touch it.

I advise you to treat it the same as backing up however many
discrete machines.  The way you do that depends on a lot of factors.
The iSCSI method is one of them.

The other issue is, just snapshotting a filesystem and taking a dump
of it is not enough to get a reliable backup.  You need to consider
the individual applications that are being run, and have ways to
tell them to stop what they are doing while you take the snapshot.
Think database servers for example.  If you can't or don't want to
deal with that, fair enough, you probably do still get a best effort
backup that saves you the majority of the time, but it's something
to be aware of.

> There should be a better way to backup the VPS' directly from the
> main server, to the FTP server, which is 1/4 the price of a
> physical server in most cases

And send your customer's data in clear over an untrusted network to
be stored on someone else's hardware?

Cheers,
Andy

Attachment: signature.asc
Description: Digital signature

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