System freezes on import

[wq9578]

Trying to import the second mirror image after putting it offline with zpool offline (causing a system freeze) again causes problems.

Executing sudo zpool import -o readonly=on -d /Volumes/MyUSBDrive/pool.mirror2.img
or sudo zpool import -o readonly=on -d /Volumes/MyUSBDrive/pool.mirror2.img pool
causes a zpool process with 100% cpu usage, which is then replaced by a launchd process with 100% cpu usage.

Upon sudo zpool import -d /Volumes/MyUSBDrive/pool.mirror2.img pool (not in readonly mode) the system freezes.

Effectively, as the first image can't be imported anymore, too, there is no access anymore to the data in the pool.

[wq9578]

Update:
I was able to import the image with: sudo zpool import -o readonly=on -N -d pool.mirror.img -a
Mounting also works: sudo zfs mount -al
But unmounting freezes the system again: sudo zfs umount -a