[GRASS-user] Using an external hard drive as data source

[Hamish]

Hanlie  wrote:
> I'm using GRASS 6.4 on two machines in different locations
> (one Win XP,
> the other Ubuntu 10.04), so I would like to keep my
> grassdata folder
> on an external drive. However, when I try to run grass in
> Ubuntu using
> the external hard drive (NTFS file system), I get the
> following error
> as soon as I've selected the new data location and the GUI
> starts to
> load:
> -----
> Execution failed: 'g.region -u -g -p -c'
> 
> Details:
> Error: MAPSET PERMANENT - permission denied
> -----
> 
> To run GRASS, I use the command 'sudo grass -wx'.
> 
> GRASS works fine when I run it from the internal hard
> drive.
> 
> Is there a way to get GRASS to work from the external
> drive?


there should be a FAQ entry for this, but I can't find it on
the wiki!?

the quick answer is that you have to mount the external hard
drive so it is owned by the same user you will run grass with.
(typically your own user account and not root, as that is much
safer).

mount -o uid=[your user id]

or add this in the /etc/fstab file.

you'll have to look in /etc/passwd to see what your user
account's UID number is.


Hamish