The reason that I did not want to offer ext3 or ext4 filesystems for the save-file is that an encrypted save-file (using cryptoloop) does not work with a journal. This is stated in the kernel documentation.
However, my workaround is that if the save-file is encrypted, it is mounted as ext2 only, ignoring any journal.
So, now at shutdown there is an extra dialog box that asks whether you want ext2, ext3 or ext4, with brief comment on the merits of each.
This involved modification to /etc/rc.d/rc.shutdown and the 'init' script in the initramfs.
Comments:Posted on 1 Apr 2010, 20:09 by Béèm
Will the initrd.gz be developped in such a way to permit this selection?
From different posts in the forum, I understand the init script in initrd.gz is to be adopted. f.e. at three places the -t ext2 is to be changed to -t ext3 if one wants to use ext3 save files.
Posted on 1 Apr 2010, 21:38 by BarryK
ext3 save file
It is all automatic. rc.shutdown saves the save-file with extension .2fs, .3fs, or .4fs depending on the filesystem, and the init script in the initrd.gz reads the filename hence knows the filesystem in it.