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Could you elaborate on that? I have some concerns about mixing the fs and raid layers. But the self healing features are attractive. And the admin utilities are a dream. I only wish that I had such a nice command-line interface to manipulate fdisk/mdadm/lvm/mkfs in the Linux world. There is no reason that this could not be done. But the fact is that, in all these years, it hasn't been done. People point me at EVMS when I speak along these lines. But EVMS really doesn't cut it. In fact, every time I check it out, I come away wondering what it is really for, and what problem it actually solves.

Furthermore, I can imagine where plain UFS is the best solution (i. e. where ZFS would be "too much of the good"), for example on systems with lower ressources or where extending the the storage "pool" won't happen. UFS is a very stable and fast file system (the article mentions this), and along with the well known UNIX mounting operations, it can still be very powerful. For example, FreeBSD uses the UFS2 file system with "soft updates". But well, these settings usually aren't places where Solaris come to use.



But remember, kids: This doesn't obsolete your accurate backups. :-)



Once you have taken the fime to read the zfs manpages, these utilities are very welcome. Especially the central zfs service program interface makes formatting and mounting very easy. It has advantages over the relatively static /etc/vfstab.

And nice to see that the Veritas volume manager has been mentioned in the article. IN VINUM VERITAS. See vinum(8) manpage. =^_^=

Edited 2008-04-21 21:38 UTC

Can't say I disagree. The layering violations are more important than some people realise, and what's worse is that Sun didn't need to do it that way. They could have created a base filesystem and abstracted out the RAID, volume management and other features while creating consistent looking userspace tools.

The all-in-one philosophy makes it that much more difficult to create other implementations of ZFS, and BSD and Apple will find it that much more difficult to do - if at all really. It makes coexistence with other filesystems that much more difficult as well, with more duplication of similar functionality. Despite the hype surrounding ZFS by Sun at the time of Solaris 10, ZFS still isn't Solaris' main filesystem by default. That tells you a lot.

a) There are no layering violations. The Linux camp keeps claiming that because it's implemented completely different than how they do their stuff. ZFS works differently, period.

b) So, what's inconsistent with zpool and zfs?

Please stop parroting one Linux developer's view. Go look at the ZFS docs. ZFS is layered. Linux developers talk crap about every thing that is not linux. Classic NIH syndrome.

ZFS was designed to make volume management and filesystems easy to use and bulletproof. What you and linux guys want defeats that purpose and the current technologies in linux land illustrate that fact to no end.



That's just plain wrong. ZFS is working fine on BSD and OS X. ZFS doesn't make coexistence with other filesystems difficult. On my Solaris box I have UFS and ZFS filesytems with zero problems. In fact I can create a zvol from my pool and format it with UFS.

What are the layering violations? Could someone point me toward some good links (or search terms) for the info?

I'm just curious if this is a "the tools aren't split out into separate fs, raid, volume, disk management tools" issue or a "source code is unreadable as everything is lumped together in one big lump" issue, or what. What are the layers of ZFS on Solaris, for example, as compared to the same layers in Linux. What's so different about FreeBSD that a single developer was able to get basic ZFS support working in under two weeks, and yet there's still no ZFS support on Linux?

Urh, you do realise that ZFS is already available in FreeBSD 7.0, right?



Export a zvol and put whatever filesystem you want on top (okay, may only UFS is directly supported, but you can use iSCSI and such to export the zvol to other systems and then put whatever FS you want on top).