On Tue, Oct 12, 2010 at 12:09:44PM -0700, Eff Norwood wrote: > The NFS client in this case was VMWare ESXi 4.1 release build. What > happened is that the file uploader behavior was changed in 4.1 to > prevent I/O contention with the VM guests. That means when you go to > upload something to the datastore, it only sends chunks of the file > instead of streaming it all at once like it did in ESXi 4.0. To end > users, something appeared to be broken because file uploads now took > 95 seconds instead of 30. Turns out that is by design in 4.1. This is > the behavior *only* for the uploader and not for the VM guests. Their > I/O is as expected.
Interesting. > I have to say as a side note, the DDRdrive X1s make a day and night > difference with VMWare. If you use VMWare via NFS, I highly recommend > the X1s as the ZIL. Otherwise the VMWare O_SYNC (Stable = FSYNC) will > kill your performance dead. We also tried SSDs as the ZIL which > worked ok until they got full, then performance tanked. As I have > posted before, SSDs as your ZIL - don't do it! -- We run SSD's as ZIL here exclusively on what I'd consider fairly busy VMware datastores and have never encountered this. How would one know how "full" their SSD being used as ZIL is? I was under the impression that even using a full 32GB X-25E was overkill spacewise for typical ZIL functionality... Ray _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
