Daniel wrote:> Hi,
>
> I wasn''t sure if this question should be directed to a Crossbow
> mailing list or Xen or NFS, as it is about all those technologies.
>
> My team and I are beginning to build a system for using Xen as a
> container to deploy a distributed system. We''re investigating
> different possibilities for how to detach the data on stateful hosts,
> to be reused by new hosts. This is to allow the upgrading of that
> host while keeping the data. One possible solution we were
> considering is using an NFS share from the dom0 mounted into local
> domU''s. We like this approach for a couple reasons but
we''re
> concerned about the performance impact. From our understanding, even
> though the filesystems will be on the local machine, using NFS will
> introduce the networking stack into all disk I/O and slow things
> down.
>
> Can using Crossbow remove the performance impact of mounting NFS from
> dom0 to local domU?
The data will still have to go through the hypervisor between domUs and
dom0, even if Crossbow is used in dom0 to do the virtual switching
between your domUs and the NFS server on dom0.
You could put together a testbed and perform some measurements to get a
better idea of the performance impact, and whether this approach would
work for your environment.
Nicolas.
>
> Thank you in advance for any help or advice.
>
> -Dan