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View Full Version : ZFS will be in Snow Leopard Server




Actuary
Jun 9, 2008, 11:37 PM
http://www.apple.com/server/macosx/snowleopard/

ZFS
For business-critical server deployments, Snow Leopard Server adds read and write support for the high-performance, 128-bit ZFS file system, which includes advanced features such as storage pooling, data redundancy, automatic error correction, dynamic volume expansion, and snapshots.



ert3
Jun 9, 2008, 11:38 PM
wow this was a feature I was pushing for.

ntrigue
Jun 10, 2008, 12:53 AM
It begins to show it merits...

dernhelm
Jun 10, 2008, 12:06 PM
Whew! I was worried there for a minute.

Honestly! But I wish they could replace HFS+ with it as the default file system. HFS+ had it's run, but honestly it needs to replaced, and if they are ever going to do it - it would be in Snow Leopard.

So the real question is why didn't they mention "bootable" in the ZFS section of the Snow Leopard pages? Please Apple - do the right thing - it may be a pretty big deal, but you've got a year to get people used to it!

If you pull it off, and make ZFS the main FS in Snow Leopard, you've got my $120 no matter what else you do!

ChrisA
Jun 10, 2008, 12:43 PM
So the real question is why didn't they mention "bootable" in the ZFS section of the Snow Leopard pages?

Think about how a bootable ZFS would have to work, you may not want it.

The boot loder written in the first sector of the disk needs to be able to understand the file system enough to read the kernal image. If the kernal image is on ZFS then either we need a REALLY HUGE first sector (not going to happen) to hold the code or we will have to limit ZF to a subset of features so the boot sector does not become to complex to fit in 512 bytes. Well, either that or Apple but special firmware in ROM to read ZFS, that means it would only work on special Apple computers that have this new firmware and it would break all existing hardware. Is there any way to have a full featured bootable ZFS on curent hardware? I can see how but maybe because I just not smart enough.

Maybe better to have a machine with a very small flash disk or HD partition containing an HFS+ file system that holds just the kernal and some system files. This would be a read-only file system. It would boot in the normal way.
As soon as this boots the first thing it does it mount the ZFS disks and then do a "chroot" into that file system. After that everything runs with ZFS. I think this has the effect you want but without ZFS being tachnically bootable and works on current hardware.

dernhelm
Jun 10, 2008, 01:33 PM
Think about how a bootable ZFS would have to work, you may not want it.

The boot loder written in the first sector of the disk needs to be able to understand the file system enough to read the kernal image. If the kernal image is on ZFS then either we need a REALLY HUGE first sector (not going to happen) to hold the code or we will have to limit ZF to a subset of features so the boot sector does not become to complex to fit in 512 bytes. Well, either that or Apple but special firmware in ROM to read ZFS, that means it would only work on special Apple computers that have this new firmware and it would break all existing hardware. Is there any way to have a full featured bootable ZFS on curent hardware? I can see how but maybe because I just not smart enough.

Maybe better to have a machine with a very small flash disk or HD partition containing an HFS+ file system that holds just the kernal and some system files. This would be a read-only file system. It would boot in the normal way.
As soon as this boots the first thing it does it mount the ZFS disks and then do a "chroot" into that file system. After that everything runs with ZFS. I think this has the effect you want but without ZFS being tachnically bootable and works on current hardware.

Yeah, it won't be an afternoon project: but some smart people got Intel Solaris booting from ZFS (I'm not sure if they fixed GRUB to "grok" ZFS, or what they did). At the time it was a bit of a hack - but I think that was only because it was done by some people in their spare time. I would think that with some concerted effort between the guys at Sun and the guys at Apple, they could come up with something so that a standard boot loader could work with ZFS too. When they migrated to HFS+ (or when windows went to NTFS) they had a similar problem and managed to overcome it.

Whatever pain they go through, will absolutely be worth it.

farbeyond
Jun 12, 2008, 04:54 PM
From Wikipedia..

"On June 6, 2007, Sun's CEO Jonathan I. Schwartz announced that Apple would make ZFS "the" filesystem in Mac OS 10.5 Leopard.[32] Marc Hamilton, VP for Solaris Marketing later wrote to clarify that, in his opinion, Apple is planning to use ZFS in future versions of Mac OS X, but not necessarily as the default filesystem for Mac OS X 10.5 Leopard.[33] In the release version of Mac OS X 10.5, ZFS is available in read-only mode from the command line, which lacks the possibility to create zpools or write to them,[34] but Apple has also released the "ZFS Read/Write Developer Preview 1.1 for Leopard",[35] which allows read-write access and the creation of zpools. The installer for the "ZFS Read/Write Developer Preview 1.1 for Leopard" is currently only working on version 10.5.0, and has not been updated for version 10.5.1 and above.[36] As of January 2008, Apple provides read-write binaries and source, but they must be installed by hand. Alex Blewitt put together an installer for the 102-A binaries, which doesn't need any hand-holding to install."

TuffLuffJimmy
Jun 12, 2008, 04:57 PM
Whew! I was worried there for a minute.

Honestly! But I wish they could replace HFS+ with it as the default file system. HFS+ had it's run, but honestly it needs to replaced, and if they are ever going to do it - it would be in Snow Leopard.

So the real question is why didn't they mention "bootable" in the ZFS section of the Snow Leopard pages? Please Apple - do the right thing - it may be a pretty big deal, but you've got a year to get people used to it!

If you pull it off, and make ZFS the main FS in Snow Leopard, you've got my $120 no matter what else you do!

I'm curious as to why you think HFS+ needs to be killed off (other than it's old) What problems are you running into in your day to day life?

crazzyeddie
Jun 13, 2008, 10:08 AM
I'm curious as to why you think HFS+ needs to be killed off (other than it's old) What problems are you running into in your day to day life?


I don't think anyone really has "problems" with HFS+, but ZFS is more stable and more capable, so its a logical upgrade.

I'm sure Apple would leave HFS+ as an option, especially for backwards compatibility reasons, but having ZFS as the default OS X installation format would be a good step in the long run.

PlaceofDis
Jun 13, 2008, 10:11 AM
while bootable ZFS would be awesome. its not something that will happen overnight. first support across the board. and then a slow transition.

Krevnik
Jun 13, 2008, 10:57 AM
Think about how a bootable ZFS would have to work, you may not want it.

The boot loder written in the first sector of the disk needs to be able to understand the file system enough to read the kernal image. If the kernal image is on ZFS then either we need a REALLY HUGE first sector (not going to happen) to hold the code or we will have to limit ZF to a subset of features so the boot sector does not become to complex to fit in 512 bytes. Well, either that or Apple but special firmware in ROM to read ZFS, that means it would only work on special Apple computers that have this new firmware and it would break all existing hardware. Is there any way to have a full featured bootable ZFS on curent hardware? I can see how but maybe because I just not smart enough.

Maybe better to have a machine with a very small flash disk or HD partition containing an HFS+ file system that holds just the kernal and some system files. This would be a read-only file system. It would boot in the normal way.
As soon as this boots the first thing it does it mount the ZFS disks and then do a "chroot" into that file system. After that everything runs with ZFS. I think this has the effect you want but without ZFS being tachnically bootable and works on current hardware.

With EFI, and Open Firmware, bootloaders are not so restrictive. If it can grok a filesystem, it can look for files at a specific path/etc. This is what Apple does. When booting, Apple's implementation of Open Firmware looks for BootX, which is the bootloader in OS X. In EFI, it is a bit more standardized: as long as you have a module for the filesystem, EFI can find 'boot.efi' and load that as the bootloader. So in reality, ZFS support is a firmware update away (if there is room).

twoodcc
Jun 13, 2008, 03:26 PM
dang, i'm looking forward to snow leopard server. it looks there are lots of reasons to upgrade to it

QuarterSwede
Jun 20, 2008, 08:23 PM
Just a little more info (http://blogs.zdnet.com/storage/?p=335) on what ZFS will do for filesystems.

ChrisA
Jun 20, 2008, 09:10 PM
With EFI, and Open Firmware, bootloaders are not so restrictive. If it can grok a filesystem, it can look for files at a specific path/etc. This is what Apple does. When booting, Apple's implementation of Open Firmware looks for BootX, which is the bootloader in OS X. In EFI, it is a bit more standardized: as long as you have a module for the filesystem, EFI can find 'boot.efi' and load that as the bootloader. So in reality, ZFS support is a firmware update away (if there is room).

I know that. My point was that a boot loader for ZFS would be quite large as it would have to have a full implementation of ZFS inside of it. What if the root ZFS file system is an array of 100+ disk drives and "BootX" has it's parts scattered all over those drives? It could be done but the firmware boot loader would have to be large, maybe to large to fit inside the flash ram in any current Apple hardware. I'm guessing that this is the case

The other option is to put restrictions on the "flavor" of ZFS that is bootable. Say maybe the files system must reside on just one disk drive.

In the end why care if ZFS is bootable? What does it get you? After the macine boots it just ignores the HFS+ boot partition as all the data is on ZFS.

hot.flyback
Nov 18, 2008, 10:38 PM
Well, guys, it surely passed a long time since January but I wanna comment a couple of things about this.
In SolarisExpress (and in extension OpenSolaris) ZFS is supported as a root filesystem.
In the recent Solaris 10/08 release there's also and option to install ZFS as root fs -this week I did it on a test server without trouble.
I think that with this feature being released in a stable Solaris, there would be no problems for the Apple engineers to implement it on Snow Leopard.

I'm also looking forward for it in OS X 'cause ZFS is really awesome!

Here are some links with insights:
http://blogs.sun.com/timf/entry/zfs_bootable_datasets_happily_rumbling
http://docs.sun.com/app/docs/doc/819-5461/zfsboot-1?a=view
And a hack: https://www.ish.com.au/solutions/articles/freebsdzfs

jpenguin
Feb 14, 2009, 07:31 PM
ZFS will be a great addition to OSX. I'm sure everyone has has data corruption with HFS+. ZFS might be a bit slower than HFS, but it will make data corruption. Although, by the time ZFS makes it to the client eddition= it will be so Apple customized they'll call it HZFS (or HFS2)