Thursday, November 03, 2005

Good Morning...

So what should I say in a first post? No idea, except to that that I'm stoked that the wait for ZFS is almost over.

If you haven't been following the details of ZFS - or you have been following by reading the trade press, which amounts to the same thing - the best recent technical description of ZFS than I know of is the set of slides that James McPherson used at the recent SOSUG4 meeting

I think it will be a great paradigm shift in how we look at filesystems. Not all the concepts are new for those of us with an interest in filesystems (pooled storage, compression, quotas and copy-on-write have been seen before in production filesystems) but it's the combination of these features with other unique approaches to performance, reliability and usability that I'm excited about.

One question nags at the back of my mind... once I have a system with large ZFS pools including many filesystems and snapshots, how do I back the whole thing up? Not just the contents of one filesystem, but the whole thing?

James mentions "real-time remote replication" so for offsite backups that may be a moot point. Sun's recent purchase of StorageTek suggests that they don't think the era of tape backup is over yet, though. Maybe the Data Management Unit (DMU) layer will do heirarchical storage...

The other intriguing aspect of James' slides is the part about using DMU as a "general purpose transactional data store". Apart from the awful, frankensteinesque beast that is UFS/zvol/DMU I think there's some real potential for innovation at this level... Reiser4 semantics on top of ZFS foundations, anyone?

1 comment:

James C. McPherson said...

Boyd, thanks for the kind words! I'll be blogging and presenting more on the DMU/OSD stuff as it develops... it's a really, really wicked concept. And re STK? The era of tape is by no means over... rotating rust requires a whole heap of electricity, tapes don't. We're on a winner with that purchase.

James C. McPherson