Re: [Xen-users] Sharing space on a SAN?

["Javier Guerra" <javier@xxxxxxxxxxx>]

On Wed, Sep 10, 2008 at 10:09 AM, Peter Van Biesen
<peter.vanbiesen@xxxxxxx> wrote:
> Both.
>
> Degradation is inherent to the concept of shared storage. Either you trust the

in this case the degradation isn't because the storage is shared; it's
because of the sync mechanisms to avoid stepping on the other
machine's toes.  And there's a world of difference between locking to
access the volume partition (CLVM/EVMS-ha) and locking at file level
(GFS/OCFS).

> I simply do not see the added value of using a clustered filesystem for a 
> domu. And in that light, any additional overhead is too much. Why make things

totally agree

but i don't find CLVM overhead any worse than LVM alone.  i asked
because you seemed to advise against it, and wanted to know if that's
because of specific experience, or just against cluster filesystems.

> Lastly, I really don't see the $/GB argument. A GB cost the same, although 
> its a bit slower on a clustered filesystem, that's all.

several not-so-big boxes with OpenFiler are A LOT cheaper than
comparable capacity NetApp settings.  the only drawback is that you
can't join/partition/migrate between boxes without help from the
block-client boxes, thus using CLVM.

> Peter.
> Ps: nice line-up of acronyms, btw 8-)

yep, OTOH, TANSTAAFL, so a11y and r9y are way down, AFAICT  :-P



-- 
Javier

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