ZFS "Dataset is busy" error

[Richard Mahlerwein]

>From: Bob Friesenhahn <bfriesen at simple.dallas.tx.us>

>To: Richard Mahlerwein <mahlerrd at yahoo.com>
>Cc: freebsd-fs at freebsd.org
>Sent: Wed, December 30, 2009 6:52:54 PM
>Subject: Re: ZFS "Dataset is busy" error
>
>>
>> Added a super simple entry to my smb.conf to allow user test to get to the shared /tank (which works fine, AFAICT), restarted all services and browsed the share from my windows host.  I dropped in half a dozen text files, then tried...
>>
>> curie# zfs list
>> NAME   USED  AVAIL  REFER  MOUNTPOINT
>> tank  70.5K  2.94G    18K  /tank
>>
>> curie# zfs snapshot tank at snap1
>> cannot create snapshot 'tank at snap1': dataset is busy
>
>This seems to have something to do with how the filesystem is mounted.
>See
>http://www.mail-archive.com/zfs-discuss@opensolaris.org/msg00812.html
>Also see
>http://defect.opensolaris.org/bz/show_bug.cgi?id=5000
>So try
>   zfs unmount tank
>   zfs mount tank
>and maybe it will start working as expected.
>
>I am finding more Google hits for FreeBSD and OS-X than I am for 
>Solaris so it may be that this issue is somewhat OS specific.

So, a completely unrelated bug with Windows and ACPI took down my machine while the VM was running.  After some tomfoolery to get filesystems cleaned back up again, I tried what you suggested...

  curie# zfs unmount tank
  curie# zfs mount tank
  curie# zfs snapshot tank at snap1
  curie#

Poof!  Success!  At least at making snapshots.  Of course, I don't yet see a "Previous Versions" tab in the properties of anything yet (which I do see on some other shares from other servers).  But at least now I can fool with those a bit.

Thanks Bob!