luks filesystem on USB device changes ownership between computers

[Martin Webster]

On Mon, 2010-08-09 at 22:37 +0100, Adam Funk wrote:

> > The problem has arisen because the file system you've used for your
> > pen drive stores the UID/GID (ownership/permissions.) LUKS isn't 
> > responsible for the problem.
> 
> I agree.
> 
> > I don't believe there is a solution... just workarounds. If file 
> > size isn't important you could format the drive with fat32 (maximum
> > file size for fat32 is 4GB.) 
> 
> File size isn't important, but security (in case the drive is lost) is
> important: that's why I'm using LUKS.

You can use LUKS with a fat32 formatted drive. Indeed, this has some
advantages as you'll be able to mount the encrypted drive from Windows
(should you wish to do so.) For example, do something along the
following lines:

sudo mkfs -t vfat /dev/sdb2
sudo luksformat /dev/sdb2

> > Alternatively, change the UID on one machine using
> > usermod:
> >
> > usermod -u <new UID> <user name>
> 
> Won't that screw up the file ownership of all sorts of things on the
> computer on which I run it? 

This automatically deals with all files in your home folder. If you have
files at other locations you'll need to change them manually.

-- 
As ever,
.\\artin

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