sharing an ext3/ext4 partition on external drive

Question

is there a way of sharing an ext3/ext4 formatted partition on an external USB drive between different users (uids) on different Linux machines without creating a group for this purpose, setting the group ownership of the partition to this group and adding each respective user to the group on every machine?

This would mean that I need to have root privileges on every machine... which I may not have in some cases.

I'm using the partition to store the code I'm developing on Linux and I would like the option to be safe... if possible.

I could use a vfat partition but then I have no control of the rw rights + I cannot develop directly in the dir: I would always have to tar.gz the directory, extract, work, tar.gz, copy to the external drive... and so on.

Thanks!

Answer 1

The general answer is "no". uid and gid on the filesystem will be as set at the moment of the write and if they don't match on a different machine, then privileges won't match either.

If you do not want to make a small revolution with uids/gids on several machines, you could try using acls to set the desired permissions for all desired users on all machines. I suspect this will use numerical uids internally, so it could happen, that giving access to your account foo on machine A, uid a, will give access to your files to a random guy bar on machine B, uid a. It also seems like it's more hassle than it's worth.

I think that saner approach would be to use tar to migrate your development tree.

I have also had a half-baked idea of carrying around a Subversion repository (with files writable only to root and appropriate access configuration files), and relying on svn server being present on all machines which you are going to use, but I do not think it's excessively sane.