Le 22 mai 07 à 01:11, Nicolas Williams a écrit :
On Mon, May 21, 2007 at 06:09:46PM -0500, Albert Chin wrote:
But still, how is tar/SSH any more multi-threaded than tar/NFS?
It's not that it is, but that NFS sync semantics and ZFS sync
semantics
conspire against single-threaded performance.
Hi Nic, I don't agree with the blanket statement. So to clarify.
There are 2 independant things at play here.
a) NFS sync semantics conspire againts single thread performance with
any backend filesystem.
However NVRAM normally offers some releaf of the issue.
b) ZFS sync semantics along with the Storage Software + imprecise
protocol in between, conspire againts ZFS performance
of some workloads on NVRAM backed storage. NFS being one of the
affected workloads.
The conjunction of the 2 causes worst than expected NFS perfomance
over ZFS backend running __on NVRAM back storage__.
If you are not considering NVRAM storage, then I know of no ZFS/NFS
specific problems.
Issue b) is being delt with, by both Solaris and Storage Vendors (we
need a refined protocol);
Issue a) is not related to ZFS and rather fundamental NFS issue.
Maybe future NFS protocol will help.
Net net; if one finds a way to 'disable cache flushing' on the
storage side, then one reaches the state
we'll be, out of the box, when b) is implemented by Solaris _and_
Storage vendor. At that point, ZFS becomes a fine NFS
server not only on JBOD as it is today , both also on NVRAM backed
storage.
It's complex enough, I thougt it was worth repeating.
-r
_______________________________________________
zfs-discuss mailing list
zfs-discuss@opensolaris.org
http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
_______________________________________________
zfs-discuss mailing list
zfs-discuss@opensolaris.org
http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
