On 2010-05-26, at 02:14, arunas.bruozis at bt.com wrote:> I?m an IT administrator and have recently started playing w/ lustre and was
wondering if there?s any way it could play with VMWare ESX as shared/distributed
storage.
> I saw your posting from ?08 (http://www.mail-archive.com/lustre-discuss at
lists.lustre.org/msg01975.html) related to lustre/VMWare, so I was wondering if
you had ever received any feedback or even implemented a solution where lustre
& VMWare ESX/4.0 ?
> Greatly appreciate any feedback/suggestions that you might have on the
topic.
I don''t really use VMs very much, but in theory it is just doing
regular file IO to the filesystem image, so running a VM on top of Lustre is no
problem at all. I''m not sure what the IO pattern from the VM would
look like, but I also assume that there is never more than a single VM with
write access to the same image file, even if the VM is doing some sort of COW
with a per-VM write delta file and a read-only full image. That will still play
nicely with Lustre because it can have proper shared read access to the full
image, and clients will get full-file write locks on their COW files and there
will not be contention.
If your question is about mounting Lustre clients WITHIN a VM to get shared
filesystem access, then I have no idea how it will behave. In theory it is
possible, but it may "hog" too much of the RAM because it will make
assumptions on cache sizes and other tunables based on the total RAM size.
The third option (I don''t know which one you are looking at) is to run
Lustre servers within the VM, which I would recommend against. This will
introduce significant performance issues, and given that Lustre is targeted at
"larger than a single server" installations, it doesn''t make
sense to use Lustre and then give it only a small fraction of the resources of a
system. You would be better off to reduce the number of OSTs and just give them
the whole server.
Cheers, Andreas
--
Andreas Dilger
Lustre Technical Lead
Oracle Corporation Canada Inc.