i also had lack of free space on my ext2 image...
since my os2008 resides on the internal mmc (mine is a n800), which is ext2 formatted _already_ and has more or less a couple of gbytes of free space, i decided to copy the entire content of the image inside the /debian folder directly.
this way i solved any issue related to lack of free space, my /debian environment soddenly became "dynamic" (it takes the exactly amount of disk space it needs), and it is much faster! (no need to mount the image as a loopback device, and no need to load other kernel modules to handle it!)
today i installed "qcad", a true cad running on my tablet... this chrooted debian trick turned my n800 in a BEAST!