qole, i tried using the script as mentioned above (passing none) but your script does a test on line 28 to see if its a real file but its not so it puts up that error message and quits.

So i hacked a condition in there (not sure if syntax is right but it worked) :
if [ ! -f "$IMGFILE" ] && [ ! -b "$IMGFILE" ] && [ "x$IMGFILE" != "xnone" ] ; then
...

and it seems to work.

Unfortunately for some reason your script seems to return immediately? I dont see how your doing the chroot any different from my old script but my old script would pause on the chroot line of script until execution completed and then i automatically clean things up. For debian i guess its best to leave things open and connected but i have multiple apps timesharing the same mountpoint(s).

First can you confirm your script is asynchronous in this way i described (script completes before the process it launches via chroot completes) ?

Then can you tell if it would be worthwhile to add that capability as an option?

As far as i can tell it otherwise worked so it may not be necessary to split things up for my purpose... but my scripts do break everything up into mount/init/run/chroot/shutdown/graft/etc operations so i wont say that would be a bad thing.

Once again don't worry too much about my program, but wanted to give feedback in case you want to support that level of control.