any help for zfs on linux continuing inability to unmount zfs file systems

[Ken D'Ambrosio]

On 2019-12-23 09:15, Harry Putnam wrote:
> Some may be familiar with this problem if using zfs on ubuntu. That is, 
> not
> being able to unmount a zfs file system... getting the message
> ". . target is busy".

That's not a ZFS problem at all.  That's what happens with any 
filesystem when you have files open and you're trying to dismount it.  
Do an "lsof | grep /mount/path/of/zfs" and you'll likely see some 
processes that are have something to do with that disk.  (That command 
may take up to a minute to execute, "depending.")  If you can kill them, 
do so, and then you should be able to umount the partition.

-Ken