Based on the fact that three of them have visited this site to defend their baby from what they see as attacks by yours truly, I imagine that the ZFS folks at Sun think I’m public enemy #1. I find that amusing because I happen to think ZFS is great. I think that there’s some misplaced emphasis on what’s great about it, there are some decisions (e.g. collapsed layering) that I believe are ill-considered, and there’s either an excess of zeal or a touch of astroturf in how it’s being touted, but simply on its technical merits and in the right context it’s great. It’s pretty darn close to the filesystem I would have written if I felt like writing a local filesystem (instead of e.g. a cluster/WAN filesystem or something completely different like what I do at Revivio) and that’s pretty much the highest praise I can offer. It’s really a shame that that gets lost in all the noise, so I’m glad of a chance to make some amends.

Paul Murphy compares ZFS to Apple’s Xserve RAID, and finds ZFS wanting. Here’s the problem: his comparison is idiotic. First, he doesn’t do any performance comparisons, or anything that even touches on the scale or data-integrity advantages that ZFS provides. His comparison is solely about ease of administration and cost, and with regard to the latter he misses something crucial.

Since I have this hangup about warranties and surprises I really don’t want to buy a no brand JBOD for this and therefore look at the Sun 3511 FC array with two pairs of 500GB drives and a standby for a total of $20,495.

What that misses is that providing the same data-integrity guarantees with cheap disks as with disk arrays is one of the cool things about ZFS. I don’t think that’s quite as earth-shaking as the ZFS folks do, for reasons explained in the second half of this comment on one of my previous threads, but it’s still cool and it bears significantly on Murphy’s comparison. The point is that for the specified application you could afford to use the cheap JBOD and get the same amount of storage in an external enclosure for about $5K — half the price of the Xserve solution. For various reasons (e.g. hot-swap capability, cache, more ports or better multi-initiator support for clusters) many people considering similar applications might want to go with at least a low-end RAID box for just a couple of grand more &mdash still well below the Xserve price. It’s just not fair to compare the Xserve to ZFS (which could run on the Xserve) plus a storage system geared toward a completely different (and less cost-sensitive) class of users. Paul Murphy thinks he’s a hacker, but he’s really just a hack.