I've been happily using XAMPP 1.7.7 on a variety of machines (Windows as well as Linux) with common htdocs and mysql databases in a FAT partition on a USB hard drive.
Apache has never been a problem but in order to get mysql to work I found I had to mount the partition with umask=000
Right now I'm on the road and limited to two machines, one of which is running Linux Mint 12 (Lisa, Gnome) without any problems and one which is running Linux Mint 14 (Nadia, KDE) and which will not allow mysql to start.
The command used to start is: sudo /opt/lampp/lampp startmysql
The error log contains the following (the computer is called "ace"):
130625 14:47:40 [ERROR] /opt/lampp/sbin/mysqld: Can't create/write to file '/home/.../xampp/mysql/data/ace.pid' (Errcode: 13)
130625 14:47:40 [ERROR] Can't start server: can't create PID file: Permission denied
so it seems to be a problem with permissions but I can't understand why it's failing.
It can happily write the err file and will delete a dummy pid if I create one so why can't it create one itself?
(I originally put the latest XAMPP on the Mint 14 machine but put 1.7.7 on it so I could reproduce exactly the working setup from the Mint 12 machine - but the same problem in both cases.)