rsync encounters chgrp errors despite --no-g

Question

I am using rsync to sync a directory to a USB-mounted device. That device automounts with myuser:root ownership. When I rsync my directory (that has myuser:myuser ownership) with -a, I get many of the following errors:

rsync: chgrp "filename" failed: Operation not permitted (1)

I tried adding --no-g after the -a option (since in this case I don't care about setting the group), but the errors persist. What do I need to do to stop rsync from trying to chgrp everything?

Solution

FAT does not have permissions; you could try either re-mounting the device with different owner/group/umask, or expanding the archive flag and removing

• "preserve permissions" flag -p
• "preserve groups" flag -g
• "preserve symlinks" flag -l
• "preserve special & device files" flag -D

Essentially rsync -rt is good enough for a FAT target.

The lazy option would be sudo rsync -a $target $dest 2> /dev/null (run as root to try and force the group change, ignore error messages).

Comments

[Will Dixon]

What filesystem is on the device?

[AbdelKh]

@Andrew: It's vfat.