On Aug 27, 2010, at 1:04 AM, Mark <markwo...@yahoo.com> wrote: > We are using a 7210, 44 disks I believe, 11 stripes of RAIDz sets. When I > installed I selected the best bang for the buck on the speed vs capacity > chart. > > We run about 30 VM's on it, across 3 ESX 4 servers. Right now, its all > running NFS, and it sucks... sooo slow.
I have a Dell 2950 server with a PERC6 controller with 512MB of write back cache and a pool of mirrors made out of 14 15K SAS drives. ZIL is integrated. This is serving 30 VMs on 3 ESXi hosts and performance is good. I find the #1 operation is random reads, so I doubt the ZIL will make as much difference as a very large L2ARC will. I'd hit that first, it's a cheaper buy. Random reads across a theoretical infinitely sized (in comparison to system RAM) 7200RPM device is a killer. Cache as much as possible in hope of hitting cache rather than disk. Breaking your pool into two or three, setting different vdev types of different type disks and tiering your VMs based on their performance profile would help. -Ross _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
