From memory, with Mac OS X 10.5.1 it was possible to use non-Apple devices (read Time Capsule) with Time Machine, but once Apple released Time Capsule and 10.5.2 was released, this was no longer possible. Since I discovered that unfortunate fact, I have not tried again to get Time Machine writing to my ZFS storage pool across the network.

Until this changes, one possibility, of course, is to just use the Mac for running applications, and write all your user data to the storage available on your ZFS NAS, which is mounted as a share on your Mac.

Would it be possible to use a ZFS NAS as a Mac backup (preferably with Time Machine)?

All I can say is this: ZFS will work on a 32-bit processor like the Pentium 4, with limited RAM. But for around $300 or so, excluding disks, you can have a superb machine — see the bottom of the ZFS hardware page. Basically, ZFS loves 64-bit processors and lots of RAM, which costs around $20 per gigabyte these days. So in the end, the solution you choose is down to how much you want to spend, and how much you value your data and access to it. Only you can make that decision. Either way, I’d love to hear what you decide and how it turns out. Good luck!

But, maybe someone can answer me this. I have an old, unused, Pentium 4 box with around (I think) 512Mb (maybe even 1Gb – it’s been a while since I even powered it up) that I haven’t had the heart to toss out. Last time I played with it it seemed to run Ubuntu ok. Is this likely to be enough for a ZFS server or should I just go out and by a cheap(ish) tower with a reliable motherboard and space for 4+ SATA drives?

I’m glad to hear that the macosforge ZFS implementation is working better than the Apple version I used from developer.apple.com a few months ago!

Yes, I’m sure FreeBSD 7.0’s ZFS implementation is very capable, but when I looked at the list of ‘incomplete/in progress’ items a month or so ago, I decided to take the ZFS implementation which I thought would be likely to give me the least trouble and, rightly or wrongly, finally decided on Solaris. I just wanted to ensure, as much as possible, to avoid ‘bleeding edge’ for the moment

For backing up 2TB of data on your fileserver, from my experience, you could build a separate backup box for around 600 euros: 300 euros for the system unit and 300 euros for the disks (no redundancy). E.g. Antec NSK6580 case + 430W PSU, Asus M2N-E motherboard, 2GB Kingston non-ECC DDR2 800 RAM, AMD BE-2350 or cheaper processor, 3 disks: WD7500AAKS, giving ~2TB non-redundant backup storage. Or, of course, if you have space, you could just chuck some more drives in your existing case and create a new backup pool

I gather there are some issues relating to spotlight on the ZFS drive, and you don’t get some free stuff like zfs share. Also, the Mac systems don’t use NFS4 so you lose the extended attribute stuff if you’re sharing via NFS (though AFP should be OK).

There seems to be not a whole lot of missing features other than ACL’s (ZFS uses WinXP/NT and NFS4 style ACLs instead of POSIX … not sure why) and out of the box iSCSI target sharing. You can still use FreeBSD’s version of iSCSI target to share a ZFS pool and/or SAMBA or NFS.

While the current Solaris version is 9 something FreeBSD “production” version is 6 … but freebsd’s CURRENT branch is pretty much up to date. Anyway I’ve been storing movies, pics, music on FreeBSD ZFS for over a year without incident. The box has over 2TB of storage and I don’t know when I’ll ever back it up

I’m on the same search for setting up ZFS for my home as you are. I’ve used the ZFS for Mac enough to verify that it works, but not to the point of stress-testing it with any sort of home production usage.