backup/restore and file permissions

[dougmon]

I've noticed that when I restore using Vortexbox backup (rsync), all of the files in my storage directory have the executable bits set and all of the directories are changed to go+w (sorry, don't know the octal mode). Originally I thought this had something to do with the rsync --perms, but after messing around a bit, I don't think that's it.

I'm kind of curious about this. Does anyone know why this is?

[durks]

I would guess it's due to the /storage directory on the Vortexbox using an ext3 (or ext4) filesystem (i.e. a native Linux one), and the backup drive using an NTFS filesystem (i.e. a native Windows one). rsync will faithfully honour permissions when copying from one native Linux filesystem to another, but the NTFS filesystem permissions structures may not be a good enough match for the Linux ones to allow rsync to do the necessary in this case.

That's just a guess, and I can't easily test it since my system (including the backup drives I use) is pure Linux. But, if you're interested, you could test the theory by doing a manual rsync as root from a source directory on /storage (just make such a directory, and copy a few files into it) to a destination one on your backup drive; and vice versa. If you do take the time to do that, post back with the results so that we can all learn something

By the way, if you want to correct the permissions you've ended up with, you could easily do so using 'find', something like as follows:

cd /storage/music/flac
find . -type f -perm 755 -exec chmod 644 {} \;

[dougmon]

Thanks. That's pretty much what i do. Why does the backup drive have to be NTFS? Or does it?

[Ron Olsen]

Thanks. That's pretty much what i do. Why does the backup drive have to be NTFS? Or does it?

VortexBox formats backup drives with NTFS since it is more portable than a Linux filesystem like ext4. Most Windows and Mac systems can read NTFS backup drives created on VortexBox. Windows and Mac do not have native support for Linux filesystems like ext4.

[dougmon]

Thanks. But there's really nothing stopping me from formatting it as ext3? The backup scripts don't seem to rely on NTFS; is that correct?

[Ron Olsen]

Thanks. But there's really nothing stopping me from formatting it as ext3? The backup scripts don't seem to rely on NTFS; is that correct?

Correct; the mount operations on the backup drive do not specify filesystem type. However, you will have to create a VortexBox.txt file (contents don't matter) on the backup drive to identify it as a VortexBox backup drive.

[dougmon]

Thanks! Very informative!