That’s because it first send sigterm, then sigkill. Then it gives up and let the kernel handle it…
Happens on my BTRFS disk’s unmount. If the kernel is currently busy handling some heavy btrfs command (like a 4tb scrub), systemd cannot stop it with sigkill.
So when it eventually gives up, you also need to wait for the kernel to finally stop the operation and actually disconnect the disk.
That’s because it first send
sigterm, thensigkill. Then it gives up and let the kernel handle it…Happens on my BTRFS disk’s unmount. If the kernel is currently busy handling some heavy btrfs command (like a 4tb scrub), systemd cannot stop it with sigkill.
So when it eventually gives up, you also need to wait for the kernel to finally stop the operation and actually disconnect the disk.