Subject: Re: [vserver] Safe to run vserver image from remote NAS/SAN ?
From: Herbert Poetzl <herbert@13thfloor.at>
Date: Mon, 11 Aug 2008 23:49:25 +0200

On Fri, Aug 08, 2008 at 10:20:45AM +0200, Gebhardt Thomas wrote:
> Hi,
> 
> is it possible (and reasonable) to put a vserver image on an central
> storage device and boot it from a host via network (maybe even on
> different hosts with individualized /var and /etc?). This would add
> even more flexibility (probably at the cost of i/o performance and
> network load) to vservers.
> 
> Brainstorming on that topic we got:
> 
> NAS/NFS:
> * no_root_squash option needed
> * is it safe? (chroot barrier!)

for NAS it depends on the filesystem used, for NFS,
we implemented NFS flag (and tagging) support for
Lycos a long time ago (they are still using it, IIRC)
but the filer needs to support those flags too

> SAN (FC or iSCSI)
> * probably a cluster filesystem is needed if vserver image is mounted
> by more than one host.

or one filesystem per guest, btw, ocfs2 has limited
Linux-VServer support

> We did not yet implement any of these setups. Certainly there are
> obstacles that we did not consider until now. Is anybody already using
> vservers in this context?

yes definitely ...

best,
Herbert

> Thanks for comments, Thomas