I wanted ZFS ...

[cesar]

... I wanted ZFS at least in Leopard Server ...

cool stuff at WWDC...

[ZachPruckowski]

I don't see it as a huge deal. Yeah, ZFS is nice, but I'm happy with Time Machine if it shakes out well. My filesystem isn't stopping me from getting big HDDs, so I'm fine with that.

Also, don't forget that some features (a few dev features, and a lot of consumer features) are still secret. We'll see more dev features in future builds (which have a bad habit of showing up on Bittorrent, not that I condone that at all), and MWSF is where they'll hype the consumer gizmos beyond what they showed. I see a late February release, just ahead of a Vista release, or possibly released at MWSF.

[hmurchison]

It's a bit early for that. Apple would need more time to implement ZFS. If all goes well perhaps 10.6 will offer it as an option. Depends on how Apple's interest remains.

[Splinemodel]

The existence of Time Machine should be able to be everything that ZFS could without slowing down disk performance.

[Ireland]

Originally Posted by ZachPruckowski

Also, don't forget that some features (a few dev features, and a lot of consumer features) are still secret.

"Time Machine" Apple said if your hard drive fails, Time machine will be able to get back all of your data. How is that possible? Is it possible this is somehow related to ZFS?? Also how would it be possible to have a 128bit file system with 32bit and 64bit systems?

[meelash]

Originally Posted by Ireland

"Time Machine" Apple said if your hard drive fails, Time machine will be able to get back all of your data. How is that possible? Is it possible this is somehow related to that this is somehow related to ZFS?? Also how would it be possible to have a 128bit file system with 32bit and 64bit systems?

Yup, there's lots of questions regarding how Time Machine "actually" works. Questions that, in my mind, will make or break it as something I'm actually going to use.

[Kickaha]

Originally Posted by Ireland

"Time Machine" Apple said if your hard drive fails, Time machine will be able to get back all of your data. How is that possible?

Pssst. You back up to *another* drive.

Is it possible this is somehow related to that this is somehow related to ZFS?? Also how would it be possible to have a 128bit file system with 32bit and 64bit systems?

Oy. You might wanna get your flame-retardant jammies on before others see this...

In short: 'Bit-ness' in one realm (CPU addressing space) has nothing to do with 'bit-ness' in another realm (internal implementation of a file system mapping approach).

[Kickaha]

Originally Posted by meelash

Yup, there's lots of questions regarding how Time Machine "actually" works. Questions that, in my mind, will make or break it as something I'm actually going to use.

My guess is that it's a slick layer over rsync + hard links. They already ship with every Mac, and make this really easy on the bottom end.

[rongold]

Originally Posted by Kickaha

My guess is that it's a slick layer over rsync + hard links. They already ship with every Mac, and make this really easy on the bottom end.

'Course, it could also rely on ZFS based on the information we have covering a similar technology (that being Spotlight) and on what that technology will be capable of doing. This is just speculation on my part though - but it certainly is possible.

[Kickaha]

Hmm. True. That would be interesting... ZFS for a dedicated backup solution only - would certainly let them hammer out working with ZFS in the real world.

Hmmmmmmm....

Interesting idea, but gut says rsync/hard links. I'm curious to see how they do it, in any case.

(Just please, don't let it be a closed database file ala Retrospect... bleah.)

[Mike Eggleston]

Originally Posted by Kickaha

My guess is that it's a slick layer over rsync + hard links. They already ship with every Mac, and make this really easy on the bottom end.

I don't think so. I think they may be using a very slick implementation of Subversion. For those of you who do not know, Subversion is a versioning software that keeps track of who changed what, and when (very simplified explanation of a very complex product).

Time Machine reeks of Subversion: which is a very good thing.

[Ireland]

Originally Posted by Kickaha

Oy. You might wanna get your flame-retardant jammies on before others see this...

In short: 'Bit-ness' in one realm (CPU addressing space) has nothing to do with 'bit-ness' in another realm (internal implementation of a file system mapping approach).

Couldn't care less 'bout what others think, I prefer to learn, I'm no geek!

Could we still see ZFS in Leopard?

[Placebo]

What does ZFS do so awesomely again?

[Kickaha]

Originally Posted by Mike Eggleston

I don't think so. I think they may be using a very slick implementation of Subversion. For those of you who do not know, Subversion is a versioning software that keeps track of who changed what, and when (very simplified explanation of a very complex product).

Time Machine reeks of Subversion: which is a very good thing.

Except that's really dumbing down svn horribly, IMO. Why toss in a really rich versioning system with all the overhead when you could just make it 'yet another volume' and use all your existing tools? Flipping back through time would be as simple as 'show me the next fileset' and have it open another directory on the disk, directly. Recover is then just a Finder copy.

I lurves svn, I use it daily - it just seems like it'd be using a 16-lb sledge to drive a finishing nail.

[Ireland]

Originally Posted by Placebo

What does ZFS do so awesomely again?

Quote from wikipedia: ZFS is a 128-bit file system, which means it can store 18 billion billion (18 quintillion) times more data than current 64-bit systems. The limitations of ZFS are designed to be so large that they will never be encountered in practice. Project leader Bonwick said, "Populating 128-bit file systems would exceed the quantum limits of earth-based storage. You couldn't fill a 128-bit storage pool without boiling the oceans."

[Placebo]

Well, I can definitely see where this is useful to you the average computer user.

[Marvin]

Originally Posted by Kickaha

Except that's really dumbing down svn horribly, IMO. Why toss in a really rich versioning system with all the overhead when you could just make it 'yet another volume' and use all your existing tools? Flipping back through time would be as simple as 'show me the next fileset' and have it open another directory on the disk, directly. Recover is then just a Finder copy.

I lurves svn, I use it daily - it just seems like it'd be using a 16-lb sledge to drive a finishing nail.

Not at all, I think it's the most efficient way of recovering changes. After being introduced to CVS etc I've actually wondered at times why versioning was never introduced in the system level. I hate having to always keep multiple copies of projects and now I don't have to. It's taking Aperture's non-destructive editing to a whole new level.

The only issue I see with it is bloat. My HD is already quite full and I'd hate for the OS to be adding GBs more to keep track of changes to files I don't need to track. It's a dilemma because I don't want to manually choose which files to track or I never will, thus making the feature redundant and I don't want it to track all my files and waste space.

Maybe I'll just need a bigger HD. Of course if they took out some bloat then I might not need it.

[Trendannoyer]

Originally Posted by meelash

Yup, there's lots of questions regarding how Time Machine "actually" works. Questions that, in my mind, will make or break it as something I'm actually going to use.

the way i read that is "ooohhh if its the wrong colour or looks a bit funny at me in the wrong light... *I* wont be backing up!...oh no!!"

well, it made me laugh

[Mike Eggleston]

Originally Posted by Marvin

The only issue I see with it is bloat. My HD is already quite full and I'd hate for the OS to be adding GBs more to keep track of changes to files I don't need to track. It's a dilemma because I don't want to manually choose which files to track or I never will, thus making the feature redundant and I don't want it to track all my files and waste space.

Maybe I'll just need a bigger HD. Of course if they took out some bloat then I might not need it.

The way I understand it is if you have a NAS or external HD, you can configure those to do the Time Machine with. I have a separate server (a Linux based one) which I have locally connected, that is basically my NAS. I think that a lot of people have some similar setups (extra Macs, an old Windows setup, etc.). Heck, even some of the External HDs out there are starting to sport NAS capabilities.

[shadow]

Someone who has Leopard: go to Spotlight and search for ZFS. Got something?

[Chucker]

Originally Posted by shadow

Someone who has Leopard: go to Spotlight and search for ZFS. Got something?

Yes. There is no file system bundle for it, nor is there a mount utility or any other one (no fsck, now newfs, etc.). There is, however, a changed vnode.h:

code:

---

enum vtagtype {
VT_NON, VT_UFS, VT_NFS, VT_MFS, VT_MSDOSFS, VT_LFS, VT_LOFS, VT_FDESC,
VT_PORTAL, VT_NULL, VT_UMAP, VT_KERNFS, VT_PROCFS, VT_AFS, VT_ISOFS,
VT_UNION, VT_HFS, VT_ZFS, VT_DEVFS, VT_WEBDAV, VT_UDF, VT_AFP,
VT_CDDA, VT_CIFS,VT_OTHER};

---

[shadow]

Originally Posted by Chucker

Yes. There is no file system bundle for it, nor is there a mount utility or any other one (no fsck, now newfs, etc.). There is, however, a changed vnode.h:

code:

---

enum vtagtype {
VT_NON, VT_UFS, VT_NFS, VT_MFS, VT_MSDOSFS, VT_LFS, VT_LOFS, VT_FDESC,
VT_PORTAL, VT_NULL, VT_UMAP, VT_KERNFS, VT_PROCFS, VT_AFS, VT_ISOFS,
VT_UNION, VT_HFS, VT_ZFS, VT_DEVFS, VT_WEBDAV, VT_UDF, VT_AFP,
VT_CDDA, VT_CIFS,VT_OTHER};

---

Not much but still encouraging. This could mean that Apple is playing with ZFS and may support it as an external filesystem sometime in the future.
*** Wishful thinking **** However, Apple could intentionally removed from the developer's build the updated / unfinished utils and references to ZFS. *** /Wishful thinking ****

[ZachPruckowski]

That seems like a change that would "break something", like someone's application, and would thus need to be to developers early so they can test it. Also, it won't draw cheers at a consumer event (more likely a string of "huh?"s)

[Chucker]

Originally Posted by ZachPruckowski

That seems like a change that would "break something", like someone's application, and would thus need to be to developers early so they can test it.

Not at all. OS X's file system support is transparent and flexible. Most applications don't care abotu the underlying file system; they access things in an agnostic manner. The biggest problem is with case-sensitiveness: some file systems are, sadly, case-sensitive (including, I believe), whereas some Mac applications, especially those building on an older foundation, expect files to be case-insensitive, and thus sometimes access the wrong file (I am, once again, looking at you, ChizenCo).

Also, it won't draw cheers at a consumer event (more likely a string of "huh?"s)

Yes.

[Kuku]

It's not quite that easy to upgrade from one file system to another.

HFS to HFS+ to HFS+ journaling..ZFS isn't quite so close-kin related.

It is quite painful and even then ZFS is still a long way to go to support apple technologies...and carbon...(and classic but it's nearly dead now).

[elron]

Originally Posted by Mike Eggleston

I don't think so. I think they may be using a very slick implementation of Subversion. For those of you who do not know, Subversion is a versioning software that keeps track of who changed what, and when (very simplified explanation of a very complex product).

Time Machine reeks of Subversion: which is a very good thing.

That's interesting. I think Time Machine looks like a nice front end for rsync. A hard drive-spanning subversion repository would be pretty cool though.l

[Mr Beardsley]

Kickaha is correct that Time Machine uses hard links, but instead of rsync it uses the same filesystem notification mechanism spotlight uses to flag files as changed. The upside is that like spotlight your system will easily know which files have been changed without having to search the whole drive. The downside is that everytime a file is changed it will have to be copied in its entirety to the backup. For small files this is no biggie, but for larger files it kinda sucks. The other downside is that Time Machine runs by default at midnight, and copies changed files for that day. Time Machine won't help you if you made several changes to a file in one day, and want to revert to an earlier state. The only choice you will have is to revert to a copy from the day before.


If you'd like to know more you can read about it over on John Siracusa's blog.

http://arstechnica.com/staff/fatbits.ars/2006/8/15/4995

[Aquatic]

So, two big questions. 1. Would there be a "button" to "push" to make it manually back changed files up immediately? I'd expect so. 2. What if I have a laptop? I won't *always* have my firewire drive plugged in, just most of the time I'm plugged in. So, half the time, or less. So...Would it be possible for it to be smart and back up changed files to the internal, then move those to the external when that is plugged in?

I'm pretty damn excited about Time Machine. Screw ZFS. Unless it's faster or something...we don't need it now. Apple seems to be able to shoe-horn anything on now regardless of HFS+'s vintage. Maybe 10.6, who cares. Time Machine--worth the $ for me alone. Easily.

[Chucker]

Originally Posted by Mr Beardsley

The other downside is that Time Machine runs by default at midnight, and copies changed files for that day. Time Machine won't help you if you made several changes to a file in one day, and want to revert to an earlier state. The only choice you will have is to revert to a copy from the day before.

Not true. There's a setting for hourly backups.

[Chucker]

Originally Posted by Aquatic

So, two big questions. 1. Would there be a "button" to "push" to make it manually back changed files up immediately?

Yep, there is.

I'd expect so. 2. What if I have a laptop? I won't *always* have my firewire drive plugged in, just most of the time I'm plugged in. So, half the time, or less. So...Would it be possible for it to be smart and back up changed files to the internal, then move those to the external when that is plugged in?

Not at this point, anyway.

[Chucker]

Note the "Backup Now" button.



Note the "Automatically" option. This means "hourly".

[Mr Beardsley]

Originally Posted by Chucker

Not true. There's a setting for hourly backups.

Excellent! Good to see the options are there.

[sjk]

Originally Posted by Mr Beardsley

Kickaha is correct that Time Machine uses hard links, …

I presume that means hard links are used within a Time Machine backup volume since they're unsupported across volumes?

If files are changed dozen of times between scheduled backup runs will all the intermediate changes be saved or only the latest revision? If the former, wouldn't there need to be some kind of cache to preserve multiple revisions until the next scheduled backup (since the TM backup volume may be temporarily unavailable between runs)? [edit: the latter part of your comment discusses that] And surely some people will prefer the TM backup volume remain offline when it's unused so it's less vulnerable to damage, with automatic mount/unmount capability available directly from TM.

[mdriftmeyer]

Originally Posted by Chucker

Yes. There is no file system bundle for it, nor is there a mount utility or any other one (no fsck, now newfs, etc.). There is, however, a changed vnode.h:

code:

---

enum vtagtype {
VT_NON, VT_UFS, VT_NFS, VT_MFS, VT_MSDOSFS, VT_LFS, VT_LOFS, VT_FDESC,
VT_PORTAL, VT_NULL, VT_UMAP, VT_KERNFS, VT_PROCFS, VT_AFS, VT_ISOFS,
VT_UNION, VT_HFS, VT_ZFS, VT_DEVFS, VT_WEBDAV, VT_UDF, VT_AFP,
VT_CDDA, VT_CIFS,VT_OTHER};

---

Recognizing filesystem types is now a sign that a specific filesystem will be used for OS X?
Take it as as sign that mount will actually be able to mount ZFS Volumes. Nice but nothing earth shattering.

[elron]

Originally Posted by sjk

I presume that means hard links are used within a Time Machine backup volume since they're unsupported across volumes?

Presumably, the first time you run Time Machine it will mirror the contents of the live disk to the backup disk. Each subsequent run will copy the files that changed to the backup disk and hard link the ones that didn't to the last changed copy on the backup disk. So you're not hard linking across volumes. They're all on the backup disk.

[sjk]

Originally Posted by elron

Presumably, …

Right. Specific TM implementation details are still presumption to anyone but "qualified" developers, excluding any valid NDA-violating information they've shared (directly or indirectly).

[Chucker]

Originally Posted by mdriftmeyer

Recognizing filesystem types is now a sign that a specific filesystem will be used for OS X?
Take it as as sign that mount will actually be able to mount ZFS Volumes. Nice but nothing earth shattering.

I was responding to a specific question. I never made any claim on whether I believe Leopard will feature ZFS, let alone be able to boot from ZFS, or even have ZFS become the default file system, nor did I claim "earth-shatteringness". As of the developer preview, none of the three apply. There are no ZFS-related utilities whatsoever as far as I can see; the only entry is the quoted vnode.h, in which the vtagtype enum changed:
- VT_UNION, VT_HFS, VT_VOLFS, VT_DEVFS, VT_WEBDAV, VT_UDF, VT_AFP,
+ VT_UNION, VT_HFS, VT_ZFS, VT_DEVFS, VT_WEBDAV, VT_UDF, VT_AFP,

Since that change involves the move to ZFS, I do believe it is notable, and I do believe, more specifically, that it answered the question that was posed.

[Marvin]

I think people generally considered that software like Time Machine would only work well with a file system like ZFS. As pointed out on these sites:

http://arstechnica.com/staff/fatbits.ars/2006/8/15/4995
http://storagemojo.com/?p=213

The best I would hope for with Leopard is that it be an option like UFS so it can be tested with external devices. Are there any changes to Disk Utility or fsck to suggest that in the Leopard preview? Maybe there's a hidden man page somewhere.

[Kickaha]

Originally Posted by Chucker

I was responding to a specific question. I never made any claim on whether I believe Leopard will feature ZFS, let alone be able to boot from ZFS, or even have ZFS become the default file system, nor did I claim "earth-shatteringness". As of the developer preview, none of the three apply. There are no ZFS-related utilities whatsoever as far as I can see; the only entry is the quoted vnode.h, in which the vtagtype enum changed:
- VT_UNION, VT_HFS, VT_VOLFS, VT_DEVFS, VT_WEBDAV, VT_UDF, VT_AFP,
+ VT_UNION, VT_HFS, VT_ZFS, VT_DEVFS, VT_WEBDAV, VT_UDF, VT_AFP,

Since that change involves the move to ZFS, I do believe it is notable, and I do believe, more specifically, that it answered the question that was posed.

Okay, so what was the VT_VOLFS that was removed?

[Chucker]

Originally Posted by Kickaha

Okay, so what was the VT_VOLFS that was removed?

http://developer.apple.com/qa/qa2001/qa1113.html

Presumably, this is being phased out, although mount_volfs still exists, whereas mount_synthfs is now gone.

(Did I mention mount_union is added? )