creating mirrored lv in background

[Ambrogio]

Hi all,

I'm trying to mirror a logical volume using lvconvert

As the LV is big I vould like to know more about the mirroring fase.

I tried with a little lv on USB keys but the process is slow. This is
not a problem, but I would like to know what appens if I loose a disk
during the process.

I can't monitor the process using lvs because it hangs until convert
completes.

I tryed also to use the -b option but the process continue in foreground
and the shell don't return the prompt until it completed.
The process is not interruptible.

It is correct what I expect about the -b option?

Tnx in advance
 Ambrogio