Considering a ZFS build

[Child of Wonder]

Currently I'm running a home built file server running Debian. It has 4x250GB WD RE3 drives connected to a Dell Perc5i in RAID 5 which I use as an iSCSI datastore for my two ESXi servers. On top of that, there are 3x1.5TB drives in software RAID 5 I use for my home file share (photos, videos, etc.).

As I begin to run more and more virtual machines, it's becoming clear my solution isn't scaling as much as I would like.

After reading about ZFS, I'm considering replacing my hardware with the following and installing FreeNAS on a USB flash drive:

AMD Athlon II X2 250
2x4GB DDR3 1333
4x250GB WD RE3 RAID-Z for iSCSI VM datastore
4x250GB WD RE3 RAID-Z for NFS VM datastore
3x2TB Samsung F4 RAID-Z for File Share
64GB SSD drive for ZFS write logging and read cache

Is it worth it getting the SSD drive? Even though I'm using the same drives, is the performance benefit of ZFS over my hardware RAID card worth the hassle? Will the configuration I'm suggesting even work?

Thanks in advance.

 

[danswartz]

I wouldn't bother with two pools. Also, ESXi works just as well with an NFS-backed datastore. Not so sure about freenas with zfs - I'd prefer OI or solaris SE11. You probably don't want the zil and read cache on the same device (for almost any home use, a read cache is little use anyway...)

 

[Child of Wonder]

I wouldn't bother with two pools. Also, ESXi works just as well with an NFS-backed datastore. Not so sure about freenas with zfs - I'd prefer OI or solaris SE11. You probably don't want the zil and read cache on the same device (for almost any home use, a read cache is little use anyway...)

I'm doing two pools so I can have a datastore with each protocol. This is part of my home lab so I fiddle with iSCSI multipathing, NFS over LACP, etc.

The read cache should be of use to me since there will be approximately 12-20 VMs at a given time running on the two datastores.

 

[danswartz]

Well, you can have any number of datastores on one pool, just create one. Like tank/esxi-iscsi and tank/nfs. Before you spend for the ssd for a read cache, let the SAN run for a few days to get the ARC hot, then run arc_summary.pl (a nifty perl script - google for it.) It will show you hit and miss rates - whether you really need an L2ARC or not. That said, you almost certainly don't want the ZIL and read cache on the same device.