Since i migrate to zfs where it is possible, i did this also with an usb storage. Today, i want to export a pool to use it in my laptop. I finished all i want to do and want to remove the zpool from my system via
zpool export mypool.
umount: /foo/bar/mypoo/foobar: target is busy. (In some cases useful info about processes that use the device is found by lsof(8) or fuser(1)) cannot unmount '/foo/bar/mypoo/foobar': umount failed
Ok, maybe it needs some time to finish writing/flushing the cache so i gave him another 15 minutes. I tried again and the same error message. I used "lsof" but nothing inside when i grep for "mypool". After taking a long look over the internet, the only solution i found was using
zpool export -f mypoolbut again, same error.
After strange threads talking about "you have to restart your usb module" i just took a look to the current running systemd units by using
systemctl list-unitsand guess what? There are units running for each mountpoint the zfs pool had. All i had to do is to stop the unites and the run "
zpool export mypoolthe last time .