ZFS Set To Eventually Play Larger Role in OSX

BlueMerle writes with the news that Sun's ZFS filesystem is going to see 'rudimentary support' under OSX Leopard. That's a stepping stone to bigger and better things, as the filesystem will eventually play a much larger role in Apple OS versions. AppleInsider reports: "The developer release, those people familiar with the matter say, is a telltale sign that Apple plans further adoption of ZFS under Mac OS X as the operating system matures. It's further believed that ZFS is a candidate to eventually succeed HFS+ as the default operating system for Mac OS X -- an unfulfilled claim already made in regard to Leopard by Sun's chief executive Jonathan Schwartz back in June. Unlike Apple's progression from HFS to HFS+, ZFS is not an incremental improvement to existing technology, but rather a fundamentally new approach to data management. It aims to provide simple administration, transactional semantics, end-to-end data integrity, and immense scalability."

Comments

Does anyone proofread these articles?

[tomRakewell]

It's further believed that ZFS is a candidate to eventually succeed HFS+ as the default operating system for Mac OS X

Macs are really going to stink if Apple changes their default operating system to ZFS. ZFS is a file system.

Re:Does anyone proofread these articles?

[McFadden]

Does anyone proofread these articles?

They haven't done for 10 years. You're expecting them to start now?

Re:Does anyone proofread these articles?

[hackstraw]

Macs are really going to stink if Apple changes their default operating system to ZFS. ZFS is a file system.

Right, and emacs is a text editor.

Re:Does anyone proofread these articles?

[stefanlasiewski]

Silly man. Everyone knows that Emacs is an operating system. It even runs VI.

Re:Does anyone proofread these articles?

[phliar]

It probably won't happen anyway. ZFS wasn't invented at Apple, and thus will never become an important part of 'The Mac.'

And Unix wasn't invented there either, but I'd call OS X "an important part of 'The Mac'".

Re:Does anyone proofread these articles?

[Durandal64]

Apache wasnt invented at Apple. Neither was Samba. Neither was SSH. Neither was gcc. All of these things are very important in Mac OS X.

Buzz compliant

[suv4x4]

end-to-end data integrity

You can't talk about end-to-end data integrity when this is just a filesystem. It's only one tiny place where the data you store in said file system can wreck its integrity. Are there memory bus or in-memory check for integrity of data read from ZFS? What about applications?

Also stop talking to ZFS. Very secret internal sources told me ZFS was supposed to be a bigger event in Leopard but Steve killed it because Sun scooped him. It has happened before folks!

Don't scoop the Steve. You scoop the Steve and business is over.

Re:Buzz compliant

[Anonymous Coward]

There is a in-memory checksum check for all data that is read, yes. If the checksum doesn't match ZFS tries to read the same data from another disk, in a mirror/RAID-Z setup.

Re:Buzz compliant

[jadavis]

Are there memory bus or in-memory check for integrity of data read from ZFS? What about applications?

They have defined what they mean by that claim already: they have a checksum (256-bit, I think) on every block, and that checksum is checked from the OS when the block is read.

This will catch some errors that might otherwise go uncaught, which is important for servers that move a lot of data around.

It will not catch a memory error at the wrong time, or a processor error that stores the wrong value, or an error in the brain of the person who reads the data from the screen.

Re:Buzz compliant

[mikeee]

IIRC, the block checksums are stored in the inode, not with the individual blocks. It turns out that one of the main failure modes of modern disks isn't reading a few bits wrong, but missing slightly on a seek and actually returning the wrong block! Block-included checksums won't find this, since it's still a valid block...

Re:So.... BSD or Solaris???

[Anonymous Coward]

Non standard tools and such

Uh, Mac OS X is certified standard UNIX. Solaris is also certified standard UNIX. And they're both fully POSIX compliant.

What are some examples of non-standard tools?

a true end

[gEvil (beta)]

Unless I'm mistaken, this will mean the true end to resource forks on the MacOS. For those of you who aren't familiar with them, resource forks were a part of a file under the Classic MacOS (OS 9 and before) that contained icon information, filetype and creator codes, etc. This part of the file was only supported under the HFS and HFS+ filesystems, meaning the resource fork would get lost if you copied a file to a non-HFS/HFS+ filesystem (this is why files copied to FAT filesystems in the old days often wouldn't reopen on a Mac. It also explains the "Mac OS X" folder with underscored-dot files from archives created with OS X's built-in zip utility). With OS X, Apple rolled the resource fork into the "data fork" portion of the file, meaning the information was still there for legacy purposes. However, this is only supported under apps that know where to find the information. This change has the potential to cause some headaches for shops that have legacy files spanning several decades. OTOH, I'll be glad to see it finally go...

Re:a true end

[Just Some Guy]

For those of you who aren't familiar with them, resource forks were a part of a file under the Classic MacOS (OS 9 and before) that contained icon information, filetype and creator codes, etc.

I'll be happy to see them kill that obsolete feature. It's hard to implement everything-is-a-file semantics when some things are files, and others are combinations of random amounts of metadata.

They said the same thing about UFS.

[argent]

They made a big deal about the import of the latest UFS from FreeBSD in Panther, and their support for UFS was actually reduced in Tiger because they put the Spotlight hooks into HFS+ instead of using the hooks already in the vnode layer in Darwin.

So don't do anything that would depend on them supporting ZFS.

Re:They said the same thing about UFS.

[Ilgaz]

I don't think UFS using community would be happy about Spotlight anyway.

Spotlight in current form tries to index every single source file, huge framework headers and there is no practical way to stop it. I have tried the Privacy pane as suggested and no, it doesn't explain my 130 MB of spotlight metadata after installing Developer tools and couple of GNU libraries.

If they have checked the NeXT history, they would figure the UFS is the default,supported Filesystem on NeXT. As OS X is a mix of NeXT with FreeBSD and Cocoa/Carbon, it is pretty natural that UFS gets into it a bit lately but finally.

I can imagine what Apple needs for supporting ZFS on startup volumes. Complete metadata and resource support. They could be happy with their ext3 plain filesystem but Apple using professionals REALLY label their files, sometimes change their icons, sometimes has to FORCE OS to open a file with a different version of suite (e.g. Quark 7 vs 6), add comments to them and professional software developers like Adobe still stores critical data on resource forks.

If there is a way to make ZFS support all those features without huge hacks (like the ZIP _resource stuff), they would give up their HFS+. Another thing is, it must support every serious software (non hack) backwards. You may find yourself using a application from 2001 written in Carbon under OS X and only it can provide the tool you require.

I am saying these since some elitists think Apple is backwards and stupid still supporting resource forks and implement special features to OS X just to give minimum compatibility with old applications.

Before critising HFS+ and suggesting Apple to use plain, Unix filesystems, they should sit around in a professional environment such as a DTP house, Movie studio and see how all those "childish" "backwards" features are used by professionals in job.

This is not a post against ZFS, I am just trying to explain why Apple can't magically move to another filesystem just because it has better features. Not even mentioning the "overhead" required by ZFS and the fact that there are some 2k/4k (Cinema) edit environments which you can't even enable journaling let alone adding another layer of overhead.

Also while writing these, if I only used plain Unix tools without any "native Mac" Application, e.g. use OS X as Darwin with X11, UFS would be my choice of filesystem.

Re:They said the same thing about UFS.

[flaming-opus]

True, but the capabilities of UFS don't really exceed HFS+. ZFS, on the other hand, is a thoroughly modern filesystem. UFS is just as rusty as HFS+.

Re:So.... BSD or Solaris???

[abigor]

Even though OSX will still be Unix, will they'll move away from BSD and toward Solaris?

I'm hoping not, since many things behave very oddly on Solaris. Non standard tools and such, but it would be one way to keep it from running on cracked PC's.

2 cents,

QueenB. Please go and stare at this page for a while: http://en.wikipedia.org/wiki/XNU

If by "non-standard tools" you mean non-GNU, yes, but they are hardly odd.

I have no idea what your "cracked PCs" comment is all about, and what it has to do with Solaris and ZFS.

Re:So.... BSD or Solaris???

[Trigun]

killall

How many people have learned that one the hard way?

I maintain:

[teknopurge]

Sun is the new Bell Labs.

Watch for the robotics coming out, very quietly, from Sun in the next 10 years.

Non-Standard my ass!

[kaiwai]

I'm hoping not, since many things behave very oddly on Solaris. Non standard tools and such, but it would be one way to keep it from running on cracked PC's.

What are you smokeing - what ever it is, pass it this way. Non-standard or 'does not conform to the bastardised standards which GNU have embraced and extended'. Case in point, look at the number of nimrods who assume gnu grep and use gnu specific switches for their make scripts.

It isn't Solaris that it is non-standard, it is those who insist on using GNU tools and their extensions to the standard which are the non-standard.

Not so. ZFS could handle resources

[Henriok]

Hardly! ZFS have provisions for any number of "forks" in the file system, called "extended attributes" in ZFS. If Apple migrates to ZFS they have every chanse to use these attributes to provide for quite a seamless integration with previous filsystems. The file system is open source and Apple can prettymuch do what they like or need. Even NTFS have these features but MS seems to ignore them due to backwards compatability issues with FAT filsystems and Windows APIs

You know.. Wikipedia is very handy to look these things up. Please do. http://en.wikipedia.org/wiki/ZFS

Re:Not so. ZFS could handle resources

[Trailer Trash]

You know.. Wikipedia is very handy to look these things up.

Dude, we're still trying to get people to read the linked article. Let's not get too crazy.

Re:Not so. ZFS could handle resources

[EvanED]

Even NTFS have these features but MS seems to ignore them due to backwards compatability issues with FAT filsystems and Windows APIs
They are starting to do some stuff with them. The first major use I know of was with XP SP2. With that, when you downloaded a file from the internet, IE would mark it as such in an alternate stream. When the program was run, someone (I don't know who) would check for the presence of the stream and if it was there, would display a "this program came from an untrusted source, would you like to run it?" dialog.

I would expect more uses as we move into the future, as Vista is pushing even heavier for NTFS (for instance, IIRC the installer didn't ask which file system I wanted to use and just formatted NTFS), and MS doesn't have to worry about, for instance, some 98 or ME user who upgraded to XP but is still running FAT so he didn't have to reformat. For my large partitions (~100 GB), I can't format as anything but NTFS. (I don't know about smaller ones; I have a 24 GB system partition but if I try to bring up the format dialog there it complains that I'm trying to reformat the drive with the OS and I don't want to do that.)

Personally, I think that there's a lot of awesome stuff that you could use extended attributes and alternate streams (WHY are these separate concepts on some file systems?!) if only they would be preserved when you move stuff around systems, upload them, etc., and am somewhat resentful at Unix and POSIX for the fact that for ages they didn't do this stuff and hence it's really hard to move to using them because no one supports them because there's no demand because people haven't thought of what to do with them because they haven't seen what can be done with them because no one uses them because no one supports them because... :-) I've often wondered what operating systems would be like if we kept the knowledge of the last decades, but threw out everything that we had now and started from scratch without worry of backwards compatibility, and this is one of the things I would like to see change.

folders are even worse

[SuperBanana]

Resource forks are far better than the idiotic "everything is a folder" model.

Want to upload that Keynote project to your friendly CMS via a web browser? Can't, because it's not a file, it's a #@$!ing FOLDER. You have to zip it first. Words cannot accurately describe how tiresome this becomes.

It also makes data recovery (should the file get accidentally deleted) nearly impossible- the files inside the folder are not named uniquely or in any identifiable manner.

ZFS isn't nearly all it is cracked up to be- among other things, you can't expand RAID-Z...absolutely moronic. I'm not even sure you can expand a simple mirrored pool. Users have been repeatedly asking for growing abilities, and the developer reaction was "just create a larger pool and move it over". That's hilariously stupid advice given that you usually don't have that kind of storage hanging around- not even in enterprise environments.

There's simply no comprehension amongst the ZFS developers that virtually EVERY raid card on the market supports such an operation. Even more shocking was when one developer said (paraphrasing) "gosh, how would one even go about doing that sort of thing?"

Don't get me wrong- checksumming and automatic disk scrubbing are features long overdue, but ZFS is not magic bullet.

Re:folders are even worse

[kithrup]

It's true that you can't expand a RAID-Z set (I think, anyway -- if you replace all of the drives, one at a time, does that work?), but you can add another RAID-Z set, and expand the pool.

That's the big thing in ZFS, combining all of the resources into a pool, rather than treating disks (or groups of disks) as part of a volume. The other part of this was making filesystems nearly as light-weight as directories.

My plan is to use twinned drives, adding them as a mirror to the pool. I can replace each drive individually, let it re-silver, and then do the same with the other, to expand it, or I can simply add another pair of drives to the pool, and get more space that way. There are advantages and disadvantages to each.

Oh, as for resource forks -- the model that Sun is choosing (as are some others) is that the extended attributes are treated as sub-files to a directory. I'm not sure that simply going to a directory is not a better idea, but that has a whole slew of its own problems. It's a bit ironic, really -- Apple had an idea from the beginning, and every application was prepared to deal with it, but nobody else did the same thing. Then, when Apple went with the flow, everyone else started trying to do what Apple did... and none of the applications are prepared for it.

I'm not sure how it'll all turn out.

Re:So.... BSD or Solaris???

[memfrob]

Uh, Mac OS X is certified standard UNIX.

According to the Single Unix Standard, only Mac OS X 10.5 (Leopard) can be considered "Unix". And only when deployed on Intel-based Macs. Previous versions must be considered like Linux: "Unix-like".

FWIW, Sun's operating system (SunOS) has been fairly close to Unix standards over its lifetime. In fact, the official version of System V release 4 was written by Sun and called SunOS 5, integrated into Solaris 2

Why is anyone even having this argument? GNU means "Gnu's NOT Unix" for a reason...

Re:Time Machine

[LKM]

Except Time Machine does not use ZFS.