OS X/FreeBSD shared zfs partition

[Wes Morgan]

On Tue, 20 Jan 2009, John Hendy wrote:

> Wow... I really didn't expect that to work! Well, it 'kind of worked'.
> Here's what I got:
>
> I did 'zpool import' and got the usual 'ZFS is experimental in FreeBSD, ZFS
> filesystem version 6' and it said something like 'you can import pools by
> name' (sorry - i missed the exact message). Then I did 'zfs lilst' and tank
> was listed, but not tank/jwhendy.

That version "6" is the pool format. The actual filesystem on-disk 
versions are different. In -current, the pool version is 13 and filesystem 
version is 3, according to both "zpool upgrade" and "zfs upgrade". Sounds 
like the zfs code in OS X is more recent than that in -stable.

> Then I did 'zfs mount tank/jwhendy' and got:
>
> 'Mismatched versions: Filesystem is version 2 on-disk format, which is
> incompatible with this software version 1! You can force  mounting with -f'
>
> I did 'zfs mount -f tank/jwhendy' and it said 'Cannot mount 'tank/jwhendy':
> Operation not supported', but zfs list shows:

Yeah I wouldn't advice doing that, no telling what will happen.

zfs list will show you filesystem status regardless of mount status, it's 
just reading the pool data I imagine.

>
> NAME USED AVAIL REFER MOUNTPOINT
> tank 11.4G 27.2G 390K /tank
> tank/jwhendy 11.4G 27.2G 11.4G /tank/jwhendy
>
> So... it appears it mounted? when I cd /tank/jwhendy, though, all that is in
> the folder is a file called .autodiskmounted, which I assume is used by OS
> X.
>
> I think we've made some progress... any way to go the whole way? Can I
> upgrade the zfs version in FreeBSD since it complains about the mismatched
> software versions? Just a thought.
>
>
>
> Thanks!
> John
>
> On Tue, Jan 20, 2009 at 1:01 PM, Boris Kotzev <boris.kotzev at gmail.com>wrote:
>
>>> Hi,
>>>
>>> I dual boot OS X and FreeBSD (currently 7.0-i386) and have wanted to
>> share a
>>> partition for storage between the two. I looked into getting HFS+ to work
>> on
>>> FreeBSD (http://forums.freebsd.org/showthread.php?t=1198)<
>> http://forums.freebsd.org/showthread.php?t=1198>
>>> but
>>> did not succeed. Then I ran across these two pages:
>>>
>>> - http://blog.igorminar.com/2009/01/using-zfs-with-mac-os-x-105.html
>>> - http://zfs.macosforge.org/trac/wiki
>>>
>>> I used them to successfully change my Users folder in OS X to a zfs
>>> filesystem on a partition separate from my main OS X system/boot files.
>> Now
>>> I just want to mount that partition from FreeBSD. Is this possible? I can
>>> see the slice in /dev as ad5s3, but there's no partitions on that slice
>> to
>>> mount (ad5s3a, for example), nor am I familiar enough with ZFS to know
>> what
>>> it should look like from FreeBSD. I have tried 'mount -t zfs /dev/ad5s3
>>> /media/temp' without success. zfs.ko is loaded (seen in kldstat) and
>> gives
>>> the usual message of it being experimental and being version 6.0. In a
>> post
>>> on the forums (http://forums.freebsd.org/showthread.php?t=1613) it was
>>> suggested that I try 'zpool list' but that returned 'no pools available'.
>> I
>>> tried 'zfs list' as well and got 'no datasets available'.
>>>
>>> My GUID partition table (OS X) and MBR (FreeBSD) are synced, so they both
>>> show disk0s3 (OS X)/partition 3 as type Solaris (It's 'Solaris Usr' on
>> the
>>> GPT and type B4 iirc on the MBR). I used an EFI booting program called
>> rEFIt
>>> to sync the tables - could the MBR type of the slice be the reason I
>> can't
>>> mount it from FreeBSD?
>>>
>>> I've searched long and hard for any posts about using zfs as a way to
>> share
>>> a partition between any two OSs, but have not found any references on how
>> to
>>> use a zfs slice as a shared data partition. Can it only be mounted from
>> the
>>> OS in which it was created? Any thoughts on what I might do here?
>>>
>>>
>>> Thanks much,
>>> John
>>
>> I am sorry, I wanted to ask what
>>
>> zpool import
>>
>> returns.
>>
>> Regards,
>>
>> Boris Kotzev