[BBLISA] filesystems supporting snapshots

[Tom Metro]

Arthur Gaer wrote:
> My understanding--from a few years ago--was that NetApp's filesystem 
> snapshot facility was something of a side-effect of NetApp's propriety 
> WAFL file system/implementation...

That's my understanding as well.

I've also wondered, given the value of that feature, why we haven't seen 
it appear in one of the community developed, open source file systems.


Jeff Wasilko wrote:
> ZFS from Sun gets you pretty much everything that Netapp has
> (filesystem-wise), and more.

I guess Sun saved the community the trouble of developing it (and 
conveniently patented all the best parts).

Sun opens ZFS source code
http://arstechnica.com/news.ars/post/20051117-5595.html

This 2005 article gives some background on ZFS and says:

   So, now that the ZFS source code is available for use, will we be
   seeing it in Linux sometime soon? According to a Sun FAQ about ZFS, a
   Linux port "is currently being investigated."


And then an article from about a year ago:
http://www.linuxinsight.com/zfs_filesystem_for_linux.html

   When ZFS was first announced, I'm sure many Linux hackers had a
   thought how it would be a great idea to port such a great filesystem
   to Linux. Unfortunately, ZFS source is distributed under Sun's CDDL
   license which is (some say deliberately) incompatible with the GPL
   license that Linux kernel uses. So, it looks like there will be no
   native port of ZFS for Linux in the foreseeable future. What a pity.

(More in the license issues here:
http://zfs-on-fuse.blogspot.com/2007/04/zfs-in-linux-kernel.html )

   Still, lurking around the web, I have found the next best thing, a
   project to port ZFS to the popular FUSE framework: ZFS on
   FUSE/Linux[1].

   Thanks to relieved FUSE licensing, which allows dynamically linking
   with it without any restrictions, it looks like it's possible to port
   ZFS to FUSE without any licensing problems. Of course, implementation
   of filesystem in userspace can never reach speed and stability of
   in-kernel filesystems, but I still find it very interesting.

1. http://www.wizy.org/wiki/ZFS_on_FUSE
and http://zfs-on-fuse.blogspot.com/

So it is already available on Linux, but in toy form. So much for 
creating a low-cost NAS using ZFS. I guess there is always FreeBSD[2].

2. http://lists.freebsd.org/pipermail/freebsd-current/2007-April/070544.html

  -Tom

-- 
Tom Metro
Venture Logic, Newton, MA, USA
"Enterprise solutions through open source."
Professional Profile: http://tmetro.venturelogic.com/