just report the 2nd experience, the 1st gone very well, a complete deleted
directory was recovered.
A tool overwritten a 2 MB text file, truncating to 0 bytes. I saw the file
listing with ls, then
switched off (with power off, no umount), then booted with a live distro,
downloaded the sources, installed needed build packages, compiled extundelete,
then run to recover the single file on the umounted partition.
It say an inode is in use, and recoved only 4096 Bytes of the file.
I looked the content of recovered file, are other textual things, not related
the overwritten file.
So total failure this time.