

ZFS for Mac OS X Breaths New Life - nilio
http://code.google.com/p/maczfs/
I'm not sure how many folks have been mourning the seeming loss of ZFS for Mac OS X for as long as I have... but I thought that this was not only great news, but a tremendous opportunity for folks to really pitch in and help a very worthwhile project for those who value their data!<p>Very exciting!
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ComputerGuru
What I'm actually more interested in is what Apple is intending on using
instead of ZFS.

All indications are that ZFS will _not_ be the next filesystem for OS X, yet
they'll need to replace HFS soon seeing as it's the worst-performing and
fewest-featured filesystem in use with this generation of operating systems.
HFS+ is showing its age in multiple places, and Apple could really take
advantage of some of the newer features available in modern filesystems to
make a huge difference and increase the power and performance behind some of
the current features (a la Time Machine), with techniques such as snapshots,
transactioned reads/writes, and more.

~~~
Someone
AFAIk the main argument against use of ZFS is that it would be relatively
resource hungry, making it a bad candidate for use in e.g. A MacBook Air. I
have Googled, but couldn't find recent data about this. Does anybody know
about any? If performance isn't good enough on some target hardware, could one
do better, or would it require dropping features? Which ones?

~~~
johnthedebs
Without encryption, compression, or deduplication on I don't think there would
be very much overheard - more than traditional file systems, definitely, but
still relatively very little.

Encryption would require significantly more CPU
(<http://forums.freebsd.org/showthread.php?t=9886>)

Compression would require moderately more CPU (depends heavily on the
compression algorithm) though you can actually speed up disk access with this
- which is the real bottleneck
([http://blogs.sun.com/observatory/entry/zfs_compression_a_win...](http://blogs.sun.com/observatory/entry/zfs_compression_a_win_win))

Deduplication requires lots of memory (I think I saw 1-2GB per TB of data
quoted someplace) and will increase CPU load a bit, but for certain workloads
can save a lot of writing and diskspace (think Virtual Images or a dataset
like Dropbox's).

I'm not involved in ZFS development (just an avid user) so take this with a
grain of salt.

~~~
newman314
With new Core iX processers now being able to do AES in hardware, I wonder if
the CPU requirement for encryption will go down significantly once/if support
is enabled.

~~~
ciupicri
Not all Core iX processors have support for the new AES instructions.

~~~
newman314
From what I can tell, most if not all of the new Sandy Bridge based Core iX
processors will.

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js2
"Breaths new life" is a bit misleading' no? From the project page: "this code
project will be used to record issues and ongoing development (if any) of this
extension"

As well, only a single commit to the git repo since July. :(

~~~
dlsspy
Depends on which one you're looking at. Alex's repo has a tremendous amount of
work. I've been doing little work since the initial build and installer since
work picked up.

I went ahead and merged mine up.

~~~
js2
Ah, I see now. Hiding on the "untested" branch. :-)

Sorry for any confusion then, and I stand corrected.

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melvinram
For those (like me) who are clueless on what ZFS is, the wiki page has a good
overview:

    
    
      In computing, ZFS is a combined file system 
      and logical volume manager designed by Sun 
      Microsystems. The features of ZFS include 
      data integrity (protection against bit rot, 
      etc), support for high storage capacities, 
      integration of the concepts of filesystem 
      and volume management, snapshots and 
      copy-on-write clones, continuous integrity 
      checking and automatic repair, RAID-Z and
      native NFSv4 ACLs.
    

<http://en.wikipedia.org/wiki/ZFS>

~~~
ihodes
ZFS is really cool. The best things that stood out out to me when I researched
it a bit a while ago (though there is so much cool about it) are

1) more storage than you could ever possibly use–you won't run out. 2) you can
add and remove drives on the fly. 3) you don't have drives you mount, you have
pools you can add to and remove from (on the fly). 4) great redundancy/error-
checking built in, in all forms.

I'd love to see it on the Mac, officially…

~~~
dlsspy
You can add and replace, but you cannot remove drives.

~~~
Andrewski
Sure you can. You just can't shrink the size of a pool.

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redial
Does anyone know if Oracle is still developing ZFS, or just Btrfs? Has the
situation changed so that Apple may include it on next iterations of OS X, or
are we stuck with HSF+ forever?

~~~
wmf
ZFS development continues; they recently released encryption support. Based on
the rumors, it sounds like Apple is now writing their own filesystem.

~~~
newman314
Too bad. I wonder why they did not throw support after btrfs if there were
licensing issues with zfs.

~~~
wmf
From Apple's perspective, Btrfs has worse licensing than ZFS.

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nilio
ZFS runs amazingly well on FreeBSD at the moment. Very, very stable and
incredible. I love having to not worry about bad blocks / sectors anymore! I
also love raid-z2 which allows 2 failed drives simultaneously. Just an amazing
comfort. We can see this on Mac OS X with some effort!

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joubert
ZFS is fantastic; it was my file system when I ran Solarid on my Sun
workstation (until I replaced it with Ubuntu).

I did get bitten once, wiping out a whole bunch of data very unexpectedly,
which I thought was a great ZFS weakness - [http://www.mail-archive.com/zfs-
discuss@opensolaris.org/msg0...](http://www.mail-archive.com/zfs-
discuss@opensolaris.org/msg09919.html)

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BonoboBoner
What I am interested in is, are there any ZFS patents that Oracle could use to
sue Apple once they eventually broadly ship ZFS?

~~~
johnthedebs
Apple won't be broadly shipping ZFS, which they made pretty clear when they
pulled it from Snow Leopard.

They haven't made an official statement, but the general consensus is that
they couldn't agree on licensing terms with Sun (ZFS is licensed under the
CDDL) and so they bailed on it. Oh how I wish they had worked things out.

That said, Oracle is also unlikely to do them any favors.

~~~
yardie
_That said, Oracle is also unlikely to do them any favors._

You can always hope. It's not like Ellison and Jobs aren't BFFs. Oracle did
write a version of their DB engine for OSX server for no, discernable, reason
at all. I don't remember any customers asking for it particularly so this
decision had to come down from way up top.

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zdw
Does this support newer zfs and zpool versions? (newer version = more
features)

Here's a list of where other platforms are at:
<http://en.wikipedia.org/wiki/ZFS#Comparisons>

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jmcnevin
I'll be that guy.

breath = noun breathe = verb

"Breathes" New Life

That is all. :)

