Check status of background destroy

[Freddie Cash]

On Fri, Jan 6, 2017 at 9:03 AM, Freddie Cash <fjwcash at gmail.com> wrote:

> On Wed, Jan 4, 2017 at 10:43 AM, Xin LI <delphij at gmail.com> wrote:
>
>> Try setting vfs.zfs.free_max_blocks to 100000 (this is an arbitrary
>> number, can be larger, limits maximum blocks being freed per txg; see
>> https://svnweb.freebsd.org/base?view=revision&revision=271532 for
>> details).
>>
>> You can inspect the progress with DTrace by looking at zfs-dbgmsg.
>>
>
> ​This is looking promising.
>
> Booting off an 11.0-based mfsBSD didn't work (locked up after "Trying to
> mount root from /dev/md0").
>
> Booting off a 10.3-based mfsBSD worked.  Set that sysctl, then imported
> the pool without issues.  The box has now been running for just over 24
> hours.
>
> ARC is sitting at 93 GB, with Wired at 116 GB.  Previously, the ARC would
> only be around 10 GB with Wired over 120 GB.  "zpool iostat" shows lots of
> reads and writes happening to the pool.  And the Avail space is slowly
> ticking upwards.
>
> Now just need to wait and see how long it takes to free up all 40 TB of
> referenced space.  :)
>
> Thanks for the info!
>
> ​Just to close out this thread, the 11.0-based mfsBSD LiveCD worked to
allow the background destroy to complete successfully.  Afterward, I was
able to import the storage pool back into the 10.3 install running off the
root pool.​  This server is back online and running normally.

Thanks for all the help and pointers everyone!

-- 
Freddie Cash
fjwcash at gmail.com