ZFS for Mac OS X Breaths New Life

http://code.google.com/p/maczfs/

by nilio • 16 years ago

70 43 16 years ago

code.google.com

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!

Very exciting!

melvinram• 16 years ago

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• 16 years ago

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…

dlsspy2• 16 years ago

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

patrickgzill• 16 years ago

The best feature is that you can tell it to do a "zpool scrub poolname" and it will go through the entire set of drives in that pool and check the checksums, correcting as necessary. Given that there are errors that can occur silently, ZFS can detect and correct them if they are single-bit errors.

js22• 16 years ago

"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. :(

anywho• 16 years ago

the forum is very active, especially alex blewitt. There are fairly infrequent updates, but it's definiatly being developed.

dlsspy2• 16 years ago

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.

js22• 16 years ago

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

Sorry for any confusion then, and I stand corrected.

nilio4• 16 years ago

I was so excited to see just how alive this is! I was hunting around and about to start the project myself when I saw this and thought everyone else would be so excited to see that a package release was just put out a few hours ago. Great to see and I think that with some support we can really help these guys along and all really enjoy some wonderful fruit.

redial• 16 years ago

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?

wmf3• 16 years ago

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

newman3143• 16 years ago

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

alwillis• 16 years ago

ZFS is more appropriate for servers; I suspect we'll see some developments in the filesystem area later this year as Mac OS X 10.7 "Lion" gets closer to shipping.

nilio4• 16 years ago

ZFS is wonderful for workstations. It keeps redundant copies of blocks and has parity functionality to keep you from having silent corruption and allowing a bad drive to sneak up on you. Running a consulting business I see many hundreds of computers yearly come in with just this problem alone for hard drive failure and ZFS would make everyone's lives so much happier just on workstations alone.

zdw4• 16 years ago

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

ComputerGuru3• 16 years ago

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.

wtallis2• 16 years ago

Don't forget about the block-level deduplication and copy-on-write which would make Time Machine use much less space.

johnthedebs5• 16 years ago

I recently got Time Machine working on a network drive that was ZFS underneath (deduplication turned on) and it didn't make a very big difference.

Deduplication would be nice, but I think it won't show a lot of benefit under many common workloads. Also, it can use up a ton of memory for larger drives (it would be a huge boon for SSDs, though).

zdw4• 16 years ago

Time Machine uses hard links within it's directory structure, so dedupe or CoW wouldn't be much help unless it was redesigned using ZFS specific features (ie, instead of rebuilding an entire hard link structure as TM does, you'd clone the TM filesystem, then apply the source changes).

Someone• 16 years ago

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?

johnthedebs5• 16 years ago

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...)

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.

petsos• 16 years ago

I don't know how resource hungry ZFS is, but the problem would be with the iOS devices, not MacBook Air.

nilio4• 16 years ago

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!

BonoboBoner• 16 years ago

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

johnthedebs5• 16 years ago

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• 16 years ago

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.

zdw4• 16 years ago

It's not CDDL - Apple has shipped dtrace for years now which is CDDL code.

Most likely, ZFS was written off for various technical reasons (large RAM requirements to run well, not optimized for portable hardware, etc.) and if there was a legal issue it was probably the NetApp lawsuit against Sun regarding ZFS.

nilio4• 16 years ago

I think a side community project is perfect given this potential concern (even though likelihood is unlikely). Oracle's not going to sue Apple for something like this.

joubert• 16 years ago

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...

jmcnevin• 16 years ago

I'll be that guy.

breath = noun breathe = verb

"Breathes" New Life

That is all. :)

ZFS for Mac OS X Breaths New Life

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