Comments on Igor Minar's Blog: Using ZFS with Mac OS X 10.5

You can still download and install the zfs-119 bui...

2009-09-18T14:30:26.808-07:00

You can still download and install the zfs-119 build, I have found that it still works without any new or unexpected issues.

ZFS was completely removed from 10.6 a few months ...

2009-09-18T12:11:59.084-07:00

ZFS was completely removed from 10.6 a few months before the release and currently doesn't have even the read-only support that 10.5 has.

It is not clear why this happened and what are the future Apple plans. There is a lot of discussion about this move on the mac zfs mailing list, but any official or even unofficial statement from Apple is missing.

http://lists.macosforge.org/pipermail/zfs-discuss

ZFS is ok on 10.6 SnowLeopard? Regards.

2009-09-18T05:08:39.938-07:00

ZFS is ok on 10.6 SnowLeopard?

Regards.

Mariano,

Yes, you are right, the best pract...

2009-04-10T20:21:00.000-07:00

Mariano,

Yes, you are right, the best practice on solaris is to give zfs the entire hard drive. But as you know ZFS port on mac can't boot (yet) and there is usually only one drive in a MBP so you don't have many options. But even if you had two disks, you supposedly wouldn't benefit much. Check out: http://alblue.blogspot.com/2008/11/zfs-119-on-mac-os-x.html?showComment=1234357560000#c6987585746077826466

My experience has been great so far. I did see 2-3 kernel panics since January, but that's a small penalty to pay for all the goodness. I haven't experienced any data loss or data corruption.

For backups I know use snapshots and I'm even able to send them to a pool on an external drive that I use for backups.

Igor, seems like we were thinking about the same w...

2009-04-10T19:51:00.000-07:00

Igor, seems like we were thinking about the same while waiting for our MacBook Pros :). All you did makes perfectly sense for me, but later, came to my mind something that I read time ago: "using ZFS is better on whole disks, rather than on slices". Googling, I have found this (from Sun, your emplooyer :)):

http://www.solarisinternals.com/wiki/index.php/ZFS_Best_Practices_Guide#ZFS_Administration_Considerations

Quoting:

"Set up one storage pool using whole disks per system, if possible.
For production systems, use whole disks rather than slices for storage pools for the following reasons:
* Allows ZFS to enable the disk's write cache for those disks that have write caches. If you are using a RAID array
with a non-volatile write cache, then this is less of an issue and slices as vdevs should still gain the benefit of
the array's write cache.
* The recovery process of replacing a failed disk is more complex when disks contain both ZFS and UFS file systems on
slices.
* ZFS pools (and underlying disks) that also contain UFS file systems on slices cannot be easily migrated to other
systems by using zpool import and export features.
* In general, maintaining slices increases administration time and cost. Lower your administration costs by
simplifying your storage pool configuration model.
If you must use slices for ZFS storage pools, review the following:
* Consider migrating the pools to whole disks after a transition period.
* Use slices on small systems, such as laptops, where experts need access to both UFS and ZFS file systems.
* However, take great care when reinstalling OSes in different slices so you don't accidentally clobber your ZFS pools.
* Managing data on slices is more complex than managing data on whole disks."

What is your experience so far with your current ZFS/HFS+ (boot) setup? It would be very useful info for me.

Thanks,
-Mariano.

@jwhendy I often need to resort to forcing the umo...

2009-02-17T05:46:00.000-08:00

@jwhendy I often need to resort to forcing the umount of a couple of my ZFS filesystems because they are busy. This is particularly true under my home directory which has selective migration to ZFS.

The rollback includes an unmount and remount. I am guessing that you could rollback if you first manually unmount.

The finder issue is that it displays pool name ins...

2009-02-16T11:50:00.000-08:00

The finder issue is that it displays pool name instead of the filesystem name in the left column and the trash issue is that you can't empty the trash via the GUI, but have to delete the items in the trash manually.

Inability to see and browse the .zfs directory is a current limitation of the mac port of zfs. In order to see and browse a snapshot you need to clone it. More info: http://zfs.macosforge.org/trac/wiki/issues

I suggest that you report the problems with rollbacks to the mac zfs team at http://lists.macosforge.org/mailman/listinfo/zfs-discuss

Thanks - I'm guessing that the 'finder issue' is t...

2009-02-14T11:42:00.000-08:00

Thanks - I'm guessing that the 'finder issue' is that it doesn't show up? The 'trash issue' is that you just delete permanently, correct?

I tried testing the snapshot feature and got something about not being able to unmount the volume when I tried a rollback. This is what I meant by the two mounting methods 'competing'. I don't think the issue was coming from the zfs side, but from the OS X side not letting the drive unmount.

Hope that made sense... what's your snapshot method and how would you go about exploring a snapshot from OS X? I didn't seem to be able to rollback and can't find a .zfs directory from which to explore the snapshot from the terminal. It is listed with 'zfs list' though - I just don't know what to do with it.

Thanks,
John

I only mounted a zfs file system as my home dir, n...

2009-02-14T08:52:00.000-08:00

I only mounted a zfs file system as my home dir, not the /Users dir and haven't experienced any issues with that (except for the small known Trash and Finder problems).

I also mounted zfs as /opt for macports and /usr/local.

I haven't had any issues with any of these mounts.

Hi,

Hopefully I'll be able to stop aski...

2009-02-14T06:26:00.000-08:00

Hi,

Hopefully I'll be able to stop asking you questions soon... I'm wondering if you think that the legacy mounting of OS X conflicts with zfs at all? I'm noticing what I think to be odd things:

- I tried to mount my pool at /Users, but the Users folder disappears from the Finder (it was an empty folder when I set this mountpoint).

- I had a 'jwhendy' filesystem at pool/jwhendy, but since /Users didn't show up, it didn't matter. I can see it from 'ls' in the terminal.

- If I 'unmount' the pool drive shown on the desktop, Users reappears and now pool/jwhendy is visible in /Users/jwhendy and zpool status and zfs list all show both pool and pool/jwhendy both mounted and online. Is OS X conflicting here?

- Lastly, I had my pool mounted at /Users again ('technically at /Volumes/Macrophage/Users') and all was well until a reboot. Now I have a /Volumes/Macrophage and a /Volumes/Macrophage 1 and neither of their Users folders shows anything inside!

Do you ever run into issues with zfs's mount and OS X's?

Thanks for any input. Should I just stick with having my zfs pools completely outside the data structure of my HD (just on / vs. /somethingElse)?

Thanks,
John

no idea, I use zfs snapshots for backups. For me t...

2009-02-08T15:09:00.000-08:00

no idea, I use zfs snapshots for backups. For me that was one of the main reasons to use ZFS in the first place.

Hi again... I gave a rest to FreeBSD for a while -...

2009-02-08T14:22:00.000-08:00

Hi again... I gave a rest to FreeBSD for a while - too busy to mess around. I have a question on backing up my zfs users folder. I set up pools tank and tank/jwhendy for my users folder. Then I changed my Users folder via the System Preferences>Accounts>ctrl click your user. So now my user folder is set to /Volumes/tank/jwhendy.

I just tried running carbon copy cloner and created a test file on the desktop to see if CCC would follow the jwhendy users folder, but it did not.

Do you have an idea of what I could do to make sure my users folder continues to be backed up if I'm using CCC?

I have seen people set up time machine with this, but having used CCC for quite a while now, I'd prefer not to have to switch my backup program.

Thanks,
John

I don't know what version of ZFS on-disk format is...

2009-01-21T09:52:00.000-08:00

I don't know what version of ZFS on-disk format is used in FreeBSD. Mac's port uses version 6 by default, but if you upgrade to the read/write build v119, you can upgrade to version 8.

Update: I did 'zpool import' in FreeBSD and then '...

2009-01-20T16:17:00.000-08:00

Update: I did 'zpool import' in FreeBSD and then 'zfs list' showed tank but not tank/jwhendy... I tried to mount tank/jwhendy with 'zfs mount tank/jwhendy' but I got 'Mismatched versions: File system is version 2 on-disk format, which is incompatible with this software version 1! cannot mount 'tank/jwhendy': operation not supported'.

Is there a way to alter the 'software versions' to match? I'm not sure what the version refers to... Since it seemed to indicate that the FreeBSD was behind OS X (1 on FBSD, 2 on OS X), I tried zpool upgrade but got 'This system is currently running ZFS version 6. All pools are formatted using this version'.

Thoughts?

Thanks,
John

yup.. that's the one.

2009-01-20T09:15:00.000-08:00

yup.. that's the one.

I'll try the mailing list. I googled OpenSolaris m...

2009-01-20T07:40:00.000-08:00

I'll try the mailing list. I googled OpenSolaris mailing list, and am wondering if the list you mean is 'zfs-discuss' on this list: http://mail.opensolaris.org/mailman/listinfo?

I'll also try FreeBSD mailing lists and already have a post on the FreeBSD forums.

Thanks,
John

No idea. I don't use Mac as a server. OpenSolaris ...

2009-01-19T19:41:00.000-08:00

No idea. I don't use Mac as a server. OpenSolaris is much better at that ;-)

Maybe try finding the corresponding terminal command, it's possible that just the GUI part is missing in Leopard.

I built a raidz zfs volume today on my office serv...

2009-01-19T19:32:00.000-08:00

I built a raidz zfs volume today on my office server.
It's made of external SATA drives.
Now, I'd like to be able to share it with the office users. However, it doesn't show up under Volumes on Server Admin under File Sharing.

Is there something I can do or is this a gotcha until we get official Apple support? TIA.

I can't remember where I saw that reference. Try a...

2009-01-19T19:04:00.000-08:00

I can't remember where I saw that reference. Try asking at the opensolaris/zfs mailing list.

I'm glad that you found the post helpful.

Excellent about sharing the partition across OS's....

2009-01-19T16:25:00.000-08:00

Excellent about sharing the partition across OS's. Your inference about what I am looking to do is exactly correct. I want disk0s3 to act as both my OS X /Users/jwhendy folder and also to be able to access the data within that folder from FreeBSD. I can see the slice from FreeBSD, but it's only showing as ad5s3 and I have not been able to mount it yet. Do you have any recollection of where the post was that you saw about sharing a partition? I haven't found anything like that using google...

I had thought about the symlink method... perhaps I will try that!

Thanks for all your input - you've been extremely helpful. I don't find many people doing this yet, so it's been great to have your input!

Thanks,
John

The statement about sharing a pool between two OSe...

2009-01-19T14:42:00.000-08:00

The statement about sharing a pool between two OSes refers to using a ZFS pool by more than one OS at the same time, ie using it as a clustered filesystem. If I understood you correctly, what you want to do is to use the pool with your Mac and later reboot (if you have a multiboot system) or move the drive to a different box and use it with FreeBSD. If that's what you want then AFAIK, it should be possible.

Regarding the mountpoints, I think what's happening is that ZFS automatically imports the pool in both boot environments. And in either case it uses the mountpoint which you defined on that fs. A quick, untested thought: what if you set the mountpoint to /Volumes/tank/jwhendy and then create a symlink from /Users/jwhendy to that mount.

Thanks for responding...

- Re. the sharing....

2009-01-19T12:04:00.000-08:00

Thanks for responding...

- Re. the sharing. I found this statement, 'A pool cannot be shared across systems. ZFS is not a cluster file system.' here: http://www.solarisinternals.com/wiki/index.php/ZFS_Best_Practices_Guide. Is that stating that I can't do what I'm trying to do in accessing one pool from two separate OSs?

- Re. the mounting issue... I have two drives: Macrophage (disk0) and Backup (disk1)

I did:
# sudo gpt add -b ##### -i 3 -s #### -t 6A898CC3-1DD2-11B2-99A6-080020736631 disk0

# sudo zpool create tank /dev/disk0s3

# sudo zfs create tank/jwhendy

# sudo zfs set mountpoint=/Users/jwhendy tank/jwhendy

Notes: since zfs was created on disk0, that's the internal drive. I got the GUID ID from wikipedia and 'sudo gpt show disk0' indicates that it is of type 'Solaris Usr', so it worked.

So... I have the zfs binaries on both drives and what I think is happening is:

- When I boot into Macrophage (disk0), tank/jwhendy gets mounted at /Users/jwhendy, which is on disk0.

- When I boot into Backup, tank/jwhendy gets mounted at /Users/jwhendy, which is on disk1 (Macrophage is still disk0, but is at /Volumes/Macrophage, not /).

What the / directory actually is depends on which drive I boot into. I want my zfs partition to only mount on the /Users/jwhendy on disk0, regardless of if it's / on disk0 or /Volumes/Macrophage on disk0.

Does that make sense?

Thanks,
John

@jwhendy I'll start with the last question. ZFS is...

2009-01-19T10:47:00.000-08:00

@jwhendy I'll start with the last question. ZFS is architecture and OS agnostic so in theory it should be possible to access your pool under FreeBSD. I've seen some references to that it works, but I haven't tried it my self.

The small inconsistencies when it comes to icons in Finder are normal. The ZFS support in Finder is not complete yet. I don't know about any workarounds, I haven't tried to find any yet.

Now, the first question regarding your mountpoints. I'm not quite sure I understand what you did and how the system is set up. If you booted from your usb drive, then I'd expect the usb drive to be mounted as /. Also you didn't make it clear where the zfs pool is located. Is it located on the usb drive or on the internal drive?

Oh, and whoops - another comment. My whole goal in...

2009-01-18T08:34:00.000-08:00

Oh, and whoops - another comment. My whole goal in this exercise was to be able to share a storage partition with FreeBSD. I could see the partition from FreeBSD as /dev/ad5s3 but could not mount it. I created a folder in /media and tried:

mount -t zfs /dev/ad5s3 /media/temp

But had no luck. I tried changing the node name to something like ad5s3[a,c,etc.] but had no luck. Will this be possible for me?

Thanks,
-John

Thanks for the response. I sat down yesterday and ...

2009-01-18T08:31:00.000-08:00

Thanks for the response. I sat down yesterday and had some good success! A few questions, though.

- First, I have a backup usb drive that is bootable as it holds my backups created with Carbon Copy Cloner. I was doing my partitioning/zfs creation from that drive. At one point I forgot I was on that drive and issued the command 'sudo zfs set mountpoint=/Users/jwhendy tank/jwhendy' but what I _should_ have done was set the mountpoint to /Volumes/Macrophage/Users/jwhendy since / was actually the backup drive.

Anyway, I rebooted and tank/jwhendy was mounted on my _internal_ drive at /Users/jwhendy. After seeing that, I suspect that it will mount with respect to the drive being booted. How can I ensure it only mounts as part of my internal drive and not the external?

-Second, the tank partition shows up as a white 'image-type' volume called tank. My Users folder still looks like a house, but when I'm in it, the finder window says 'tank' at the top and the house logo for the folder in the quick-links in the Finder side menu also says tank next to it. Is this common? Is there any way to trick it further and have this be a little more seamless?

Thanks a ton for your help!
-John

Comments on Igor Minar's Blog: Using ZFS with Mac OS X 10.5

You can still download and install the zfs-119 bui...

ZFS was completely removed from 10.6 a few months ...

ZFS is ok on 10.6 SnowLeopard? Regards.

Mariano,Yes, you are right, the best pract...

Igor, seems like we were thinking about the same w...

@jwhendy I often need to resort to forcing the umo...

The finder issue is that it displays pool name ins...

Thanks - I'm guessing that the 'finder issue' is t...

I only mounted a zfs file system as my home dir, n...

Hi,Hopefully I'll be able to stop aski...

no idea, I use zfs snapshots for backups. For me t...

Hi again... I gave a rest to FreeBSD for a while -...

I don't know what version of ZFS on-disk format is...

Update: I did 'zpool import' in FreeBSD and then '...

yup.. that's the one.

I'll try the mailing list. I googled OpenSolaris m...

No idea. I don't use Mac as a server. OpenSolaris ...

I built a raidz zfs volume today on my office serv...

I can't remember where I saw that reference. Try a...

Excellent about sharing the partition across OS's....

The statement about sharing a pool between two OSe...

Thanks for responding...- Re. the sharing....

@jwhendy I'll start with the last question. ZFS is...

Oh, and whoops - another comment. My whole goal in...

Thanks for the response. I sat down yesterday and ...

Mariano,

Yes, you are right, the best pract...

Hi,

Hopefully I'll be able to stop aski...

Thanks for responding...

- Re. the sharing....