Adam Moskowitz wrote: > I need to create and populate EXT2 image files; that is, files that > contain an EXT2 image and could be mounted like so: > > mount -o loop ext2.img /mnt > > I know how to create the file (dd) and format it as an EXT2 image > (mke2fs), but here's the catch: I need to be able to do the equivalent > of mkdir, cp, chown, chmod, and chgrp *WITHOUT MOUNTING THE IMAGE FILE*, > and to be able to do all of this from a script. > > Ideally it would look something like this: > > #!/bin/bash > . . . > dd if=/dev/zero of=ext2.img bs=1024 32768" > mke2fs -F ext2.img > . . . > magic_ext2_prog -f ext2.img mkdir /another-dir > for f in some-dir/* ; do > magic_ext2_prog -f ext2.img cp $f /another-dir > magic_ext2_prog -f ext2.img chown adamm:adamm /another-dir/$f > magic_ext2_prog -f ext2.img chmod 0644 /another-dir/$f > done > > I know about the program "debugfs," and it will let me do some of what I > want (mainly using the "-R request" option), but the man page warns that > debugfs isn't really meant for this and has some trough edges (which > worries me a bit); also (and more problematic), I don't see a way to use > the "modify_inode" request from "-R". > > Does anyone know of other tools that will let me populate an EXT2 image > file, again, *WITHOUT* mounting the file? > > Thanks, > AdamM > Oh, definitely take a look at knoppix and/or unionfs. It does what I think you are looking for. It works with an original ISO and cloop unionfs to keep the backing-store image read-only while making a writable write-aside copy in memory that you can modify. It's how they enable you to boot a linux on a CD and still do device discovery and manipulation for your hardware as well as allowing you to edit files. Every time there is a write, it gets written elsewhere and the original backing store remains unmodified.
http://www.knoppix.net/wiki/Cloop http://www.fsl.cs.sunysb.edu/project-unionfs.html _______________________________________________ Discuss mailing list Discuss@lopsa.org http://lopsa.org/cgi-bin/mailman/listinfo/discuss This list provided by the League of Professional System Administrators http://lopsa.org/
