[Linux-cluster] Mirroring Disk's Across the network

[gwood at dragonhold.org]

On Tue, Dec 27, 2005 at 07:45:22PM +1300, Tristram Cheer wrote:
> Good Afternoon All,
> 
> I'm looking for a way for us to mirror GFS volumes from a 500gb Raid5 
> Array (Non-San) to another volume in a server 100km away, we have a 
> 100mbit link to this server and the purpose of it is to offsite backup 
> the GFS volume incase of Critical Failure. Is anyone aware of a 
> production ready method to doing this?
It's the sort of thing that you should be able to do quite easily with
DRBD - but unfortunately that (AFAIK) can't be laid over the top of an
existing filesystem - so you'd probably have to do something nasty to
get it working with the existing data.  I think the DRBD device is
slightly smaller than the underlying data device (DRBD metadata), and
I'm not sure whether it takes that space from the beginning or the end -
and either could possibly destroy files/metadata anyway.

All of the standard options should work with GFS that work with anything
else - as long as you're willing to stay 5-10 minutes behind, something
like rsync should be able to do it fine.

Graham