zfs discuss - Sep 2008 - How to release/destroy ZFS volume dedicated to dump ?

Hi,

I have successfully created dedicated ZFS volume for dump
device and activated it using dumpadm(1M) command:

# zfs create -b 131072 -V 2048m data/dump
# dumpadm -n -d /dev/zvol/dsk/data/dump
      Dump content: kernel pages
       Dump device: /dev/zvol/dsk/data/dump (dedicated)
Savecore directory: /var/crash/tia
  Savecore enabled: no

Now I would like to destroy ZFS pool "data", but I am not sure,
how I might release the dump device - "zpool destroy" as well
as "zfs destroy" complain in following way:

# zpool destroy -f data
cannot remove device links for ''data/dump'': dataset is busy

# zfs destroy -f data/dump
cannot remove device links for ''data/dump'': dataset is busy

I have looked at dumpadm(1M) manpage, but haven''t found
similar approach I used for swap(1M) - I was able to release
swap ZFS volume using "swap -d".

Is there any way to release dump ZFS volume after it was
activated by dumpadm(1M) command ?

Thank you,
Jan

On Mon, 8 Sep 2008, jan damborsky wrote:
> Is there any way to release dump ZFS volume after it was activated by 
> dumpadm(1M) command ?
Try ''dumpadm -d swap'' to point the dump to the swap device.


Regards,
markm

Hi Mark,

Mark J Musante wrote:
> On Mon, 8 Sep 2008, jan damborsky wrote:
>
>> Is there any way to release dump ZFS volume after it was activated by 
>> dumpadm(1M) command ?
>
> Try ''dumpadm -d swap'' to point the dump to the swap
device.
That helped - since swap is on ZFS volume (which can''t be
utilized as dump device), ''dumpadm -d swap'' set dump to
''none'' -
thus releasing dump ZFS volume:

# swap -l
swapfile             dev    swaplo   blocks     free
/dev/zvol/dsk/data/swap 253,2        16  4194288  4194288
# dumpadm -d swap
dumpadm: no swap devices could be configured as the dump device
# dumpadm
      Dump content: kernel pages
       Dump device: none (dumps disabled)
Savecore directory: /var/crash/tia
  Savecore enabled: no
# zfs destroy data/dump ; echo $?
0
#


Thanks a lot !
Jan