Re: vfs.zfs.vol.recursive hang makes it impossible to mount zvol

From: Alexander Motin <mav_at_FreeBSD.org>
Date: Tue, 08 Nov 2022 00:43:30 UTC
On 07.11.2022 18:53, Dan The Man wrote:
> router:~ # sysctl vfs.zfs.vol.recursive=1
> vfs.zfs.vol.recursive: 0 -> 1
> router:~ # zpool import
>     pool: testing
>       id: 8013833172609421701
>    state: ONLINE
>   action: The pool can be imported using its name or numeric identifier.
>   config:
> 
>          testing                   ONLINE
>            zvol/zroot/asterisk2p3  ONLINE
> router:~ # zpool import -fR /mnt testing
> 
> This hangs forever....
> The only way to import that pool from the zvol that I know of.....

Mounting ZFS from ZVOLs is blocked for a reason.  It causes deadlocks 
due to lock recursion.  I don't know what you are trying to achieve, but 
as alternatives, the ZVOL can be passed inside VM, it can be shared via 
iSCSI (even inside the host itself), etc.

-- 
Alexander Motin