[EMAIL PROTECTED] wrote on 06/27/2008 03:39:41 AM:
> I'm likely to be building a ZFS server to act as NFS shared storage > for a couple of VMware ESX servers. Does anybody have experience of > using ZFS with VMware like this, and can anybody confirm the best > zpool configuration? > > The server will have 16x 500GB SATA drives, with dual Opteron CPU's > and 8GB of RAM. Dual parity is a must, as are hot spares. > > My first thoughts were to use raid-z2, with 2 hot spares and a zpool > made up of two 7 drive raid-z2 volumes, giving me 5TB of storage. you will get two disks worth of thruput with this setup. This is not good. > > However, I'm pretty sure VMware likes good random read performance, > so I'm considering one hot spare and a zpool made up of 5x three > disk mirror volumes. It's only 2.5TB of storage, but that should be > plenty, and I'd rather have good performance. This is what I would go with. > > Can anybody confirm that random read performance is definitely > better with mirrored volumes. Does ZFS use all the disks in the > mirror sets independently when reading data? Am I right in thinking > I could have around 7x better random read performance with the 15 > mirrored drives, when compared to the two raid-z2 volumes? Yes. two caveats though. ZFS is a COW filesystem, currently with no defrag. Placing heavy write (vmware is) on this type of storage (especially, but not only if you are planning on using snapshots) you will tend to see diminishing performance over time. Do not allow the ZFS partition to become over 80% full -- performance hits a wall hard with the kind of write profile you are going to expect with vmware as zfs looks for free blocks. test test test. -Wade > > thanks, > > Ross > > > This message posted from opensolaris.org > _______________________________________________ > 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
