Sharing a ZFS drive between FreeBSD and OS X.
irkkaaja
a partition on the laptop HDD between OS X and FreeBSD. I will
probably only ever mount it when booting and unmount it when shutting
down, so... that's good, right?
I'm guessing, based on the post about using a zpool in both OS X and
Solaris, that ZFS is compatible between FreeBSD and OS X.
Which version of Mac ZFS do I use? Specifically, this:
http://code.google.com/p/maczfs/
or this:
https://github.com/dustin/mac-zfs
And, from y'all's expert opinions, is the Mac ZFS project at a stage
where this is a good idea, or a terrible one?
Harald Hanche-Olsen
> Heya. I'm "inheriting" a MacBook from a friend. I would like to share
> a partition on the laptop HDD between OS X and FreeBSD. I will
> probably only ever mount it when booting and unmount it when shutting
> down, so... that's good, right?
> I'm guessing, based on the post about using a zpool in both OS X and
> Solaris, that ZFS is compatible between FreeBSD and OS X.
Technically yes, but I have had a lot of bad experiences with this.
First, beware of filenames containing non-ASCII characters. Any such
filename needs to be encoded in utf-8 with osx's peculiar
normalization, or you won't be able to access the file on osx, not
even to delete it.
But worse, I have had some ACL related problems, with files I created
on osx being unreadable by me on freebsd.
Also, I've had lots of crashes on osx while accessing filesystems that
have previously been mounted on freebsd, while other zfs related
crashes on osx have been quite rare.
However these experiences are from way back in the first half of 2009.
After that I was away from home and my freebsd systems for a whole
year, and after I came back I have not been tempted to try again.
(My desktop is now linux, and I use freebsd only for file servers.)
So maybe things have improved.
> And, from y'all's expert opinions, is the Mac ZFS project at a stage
> where this is a good idea, or a terrible one?
Oh, you wanted an expert opinion? I am not really an expert.
- Harald
Bjoern Kahl
> Heya. I'm "inheriting" a MacBook from a friend. I would like to share
> a partition on the laptop HDD between OS X and FreeBSD. I will
> probably only ever mount it when booting and unmount it when shutting
> down, so... that's good, right?
> I'm guessing, based on the post about using a zpool in both OS X and
> Solaris, that ZFS is compatible between FreeBSD and OS X.
In theory, they are compatible. BUT there are some things to keep in mind:
First and most important: MacZFS runs an ancient pool version. I don't
know at which pool version (the on-disk data layout) FreeBSD is, but almost
certainly it is new then the pool version 8 from MacZFS. This means:
- FreeBSD should read any pool created with MacZFS without problems
- MacZFS will not read a pool created on FreeBSD
Filesystem encoding can be a problem, it depends on ZFS for FreeBSD is
configured, and may be on other parameters I am not aware of.
MacZFs is still work inprogress, it can crash from time to time or
misbehave in other ways.
That said, I have successfully shared a ZFS pool between MacZFS and Linux
(not *BSD) in the past. I could read and write on both sides.
> Which version of Mac ZFS do I use? Specifically, this:
> http://code.google.com/p/maczfs/
> or this:
> https://github.com/dustin/mac-zfs
> And, from y'all's expert opinions, is the Mac ZFS project at a stage
> where this is a good idea, or a terrible one?
As far as I know, the version on google.com is more recent. You should try
a 74.0.x release (if you are on Leopard or Snow Leopard) or 74.1.x if you
run MacOSX Lion.
Best
Björn
--
| Bjoern Kahl +++ Siegburg +++ Germany |
| "googlelogin@-my-domain-" +++ www.bjoern-kahl.de |
| Languages: German, English, Ancient Latin (a bit :-)) |
Derek Day
On Mar 8, 2011 12:23 PM, "Bjoern Kahl" <googl...@bjoern-kahl.de> wrote:
>
> Am Tuesday 08 March 2011 schrieb irkkaaja:
> > Heya. I'm "inheriting" a MacBook from a friend. I would like to share
> > a partition on the laptop HDD between OS X and FreeBSD. I will
> > probably only ever mount it when booting and unmount it when shutting
> > down, so... that's good, right?
> > I'm guessing, based on the post about using a zpool in both OS X and
> > Solaris, that ZFS is compatible between FreeBSD and OS X.
>
> In theory, they are compatible. BUT there are some things to keep in mind:
> First and most important: MacZFS runs an ancient pool version. I don't
> know at which pool version (the on-disk data layout) FreeBSD is, but almost
> certainly it is new then the pool version 8 from MacZFS. This means:
> - FreeBSD should read any pool created with MacZFS without problems
> - MacZFS will not read a pool created on FreeBSD
MacZFS should read the pool as long as you create the pool on FreeBSD with a pool version supported by your MacZFS version.
Alex Blewitt
> Am Tuesday 08 March 2011 schrieb irkkaaja:
>> Heya. I'm "inheriting" a MacBook from a friend. I would like to share
>> a partition on the laptop HDD between OS X and FreeBSD. I will
>> probably only ever mount it when booting and unmount it when shutting
>> down, so... that's good, right?
>> I'm guessing, based on the post about using a zpool in both OS X and
>> Solaris, that ZFS is compatible between FreeBSD and OS X.
>
> In theory, they are compatible. BUT there are some things to keep in mind:
> First and most important: MacZFS runs an ancient pool version. I don't
> know at which pool version (the on-disk data layout) FreeBSD is, but almost
> certainly it is new then the pool version 8 from MacZFS. This means:
> - FreeBSD should read any pool created with MacZFS without problems
> - MacZFS will not read a pool created on FreeBSD
(unless FreeBSD was created with zpool create -o version=8 and the filesystem was created with -o version=1 - but this isn't the default.)
>> Which version of Mac ZFS do I use? Specifically, this:
>> http://code.google.com/p/maczfs/
> As far as I know, the version on google.com is more recent. You should try
> a 74.0.x release (if you are on Leopard or Snow Leopard) or 74.1.x if you
> run MacOSX Lion.
All the work I've been doing is from my GitHub repository, at http://github.com/alblue/mac-zfs/ which is the source for the binary installers at http://code.google.com/p/maczfs/downloads/list - in any case, the Git commit is recorded in the Info.plist so you should be able to determine what the source was, regardless of which repository you have pulled from.
You should be able to use MacZFS 74.1.0 for any system; the binary is the same for that and MacZFS 74.0.1 in any case, just that the installer lets you install on a Lion system. If I hear of success stories then I'll make that the featured one and push 74.0.1 to relegated status.
Alex
Sean M. Collins
7.1 & 8.1 are using ZFSv14
7-STABLE & 8-STABLE are using v15
-CURRENT (9.0) just merged in v28 support.
At the present time, plans are in place to MFC ZFSv28 to the 7-STABLE
& 8-STABLE branches
(http://www.mail-archive.com/svn-sr...@freebsd.org/msg10771.html)
in a little less than a month.
Alex has done a great job keeping this project going, but obviously
without a community around the Darwin kernel, progress is difficult.
--
Sean Collins
Core IT Pro LLC
www.coreitpro.com
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Dan Bethe
> - FreeBSD should read any pool created with MacZFS without problems
> - MacZFS will not read a pool created on FreeBSD
a version 8 zpool using another implementation (10a286, Solaris, etc)
and used it just fine on MacZFS 74. This basic backward compatibility
was always designed into ZFS, and there are no critical and
intractable reasons why a higher version than 8 is required for
personal use anyway.
> MacZFs is still work inprogress, it can crash from time to time or
> misbehave in other ways.
vague aspersions upon the product, and you could say that about
absolutely any product ever invented. :) MacZFS 74 is a fully stable
release, vetted by countless people in a diversity of large
deployments for about the last year or so, and backed up by the
presence of absolutely minimal crash reports, and most notably, a lack
of loss of any data. It is to be compared venerably with any storage
system at any price on MacOS, and held to the highest standards.
> As far as I know, the version on google.com is more recent. You should try
> a 74.0.x release (if you are on Leopard or Snow Leopard) or 74.1.x if you
> run MacOSX Lion.
stable branch! :)
Dan Bethe
> I'm guessing, based on the post about using a zpool in both OS X and
> Solaris, that ZFS is compatible between FreeBSD and OS X.
implementations on all platforms, as long as you create it with the
lowest common denominator of version number, which is a zpool version
8 and a zfs version of 2. You can mount and unmount that zpool on any
platform, rebooting between MacOS, Linux (either in FUSE or either of
the two kernel-based products), FreeBSD, Solaris (proprietary Solaris
Express, OpenIndiana, etc), or whatever. I've done some of that
myself, making a v8 zpool in OpenIndiana or in Apple's 10a286 and then
mounting it in 74, or making one in 74 and then scrubbing it with zfs-
fuse on Fedora.
I would say that ZFS has totally overtaken good old ext2 and UFS for
cross-platform storage compatibility for exactly your scenario.
> Which version of Mac ZFS do I use? Specifically, this:http://code.google.com/p/maczfs/
> or this:https://github.com/dustin/mac-zfs
quite some time, and I believe it has incorporated all truly
substantial progress from the other forks.
Come to #mac-zfs on irc.freenode.net if you want realtime assistance
or to hang out! We just got another new MacZFS user online today, so
everybody come say hi to W0nka! \o/
Harald Hanche-Olsen
> ZFS is designed to be completely compatible between all
> implementations on all platforms, [...]
> I would say that ZFS has totally overtaken good old ext2 and UFS for
> cross-platform storage compatibility for exactly your scenario.
That is one big reason why I adopted ZFS on the mac rather early on.
Maybe too early? For I did have problems. Nobody has responded to this
message of a few days back:
[Harald Hanche-Olsen <han...@math.ntnu.no> (2011-03-08 16:48:29 UTC)]
> But worse, I have had some ACL related problems, with files I created
> on osx being unreadable by me on freebsd.
I worry a little bit that the reason is that hardly anybody has tried
much moving ZFS volumes between the two OSes. Can anybody enlighten me
about ACLs? Are their format and semantics specified as part of ZFS,
or is it more or less up to each OS to handle them? If the latter,
that would explain my problems. It would also limit the usefulness of
ZFS as a cross-platform filesystem.
Er, oh, wait a bit. I was just reading about ACLs on wikipedia
(http://en.wikipedia.org/wiki/Access_control_list) and there I learn
that ACLs come in two flavours, POSIX.1e and NFSv4, with FreeBSD and
OSX, plus Solaris with ZFS using the latter. So maybe my problems were
with bugs in either implementation of NFSv4 ACLs. In which case there
is a good chance that those bugs have been fixed by now. I should try
it some day.
- Harald
Alex Blewitt
> [Dan Bethe <smuc...@gmail.com> (2011-03-10 02:18:18 UTC)]
>
>> ZFS is designed to be completely compatible between all
>> implementations on all platforms, [...]
>> I would say that ZFS has totally overtaken good old ext2 and UFS for
>> cross-platform storage compatibility for exactly your scenario.
>
> That is one big reason why I adopted ZFS on the mac rather early on.
> Maybe too early? For I did have problems. Nobody has responded to this
> message of a few days back:
>
> [Harald Hanche-Olsen <han...@math.ntnu.no> (2011-03-08 16:48:29 UTC)]
>
>> But worse, I have had some ACL related problems, with files I created
>> on osx being unreadable by me on freebsd.
>
> I worry a little bit that the reason is that hardly anybody has tried
> much moving ZFS volumes between the two OSes. Can anybody enlighten me
> about ACLs?
I'm not sure if MacZFS 74 has any ACL support; I think it's just POSIX compatible.
A bunch of new ACL got added in MacZFS 77 and later but I had to temporarily disable it whilst I work on the reclaim panic.
Even then, OSX has it's own view of the world with respect to ACL so the Solaris code paths aren't used.
The summary is thus ACLs are theoretically possible for some future version of MacZFS but probably can't be used unless you have access to the old Apple bits.
There is an issue on google code; mark yourself as a watcher on that for any updates.
Alex