Check status of background destroy

[Gary Palmer]

On Wed, Jan 04, 2017 at 10:48:28AM -0800, Freddie Cash 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.
> >
> 
> ???Forgot to mention, this server is running 64-bit FreeBSD 9.3-p5.???  That
> sysctl OID doesn't exist.
> 
> ???From the sounds of the comments on that revision, this would probable be a
> useful feature to have.
> 
> I'll have to see about upgrading this system (there's a separate pool for
> the OS), I guess.
> 
> Which FreeBSD version(s) include that feature?  Would 10.3 be okay, or
> would I have to go all the way to 11.0?

The sysctl is in 10.3

$ uname -r
10.3-RELEASE-p15
$ sysctl -d vfs.zfs.free_max_blocks
vfs.zfs.free_max_blocks: Maximum number of blocks to free in one TXG
$ sysctl vfs.zfs.free_max_blocks
vfs.zfs.free_max_blocks: 18446744073709551615
$ 

Regards,

Gary