I am posting this here because it is not really distro specific and I think it is somewhat basic although the answer may not be
I am in the process of "trying" a new distro - CentOS 5.6 - on my Ubuntu 10.04 PC.
The PC when running Ubuntu has two hard drives installed. The OS is on /dev/sda1, /home is on /dev/sda2 and most of my data files are on /dev/sda3 which is mounted as /data. Swap is on /dev/sda4. The second hard drive has one partition /dev/sdb1 mounted as /quitelarge (it is a 1 TB drive! so it was large when I purchased it). I have a nightly batch program which archives important data files from /data to /quitelarge/mirror.
To "try" CentOS I physically removed the /dev/hda drive and substituted another drive. I have CentOS installed on the new /dev/sda which is partitioned the same way as I described above for the Ubuntu disk. I have the nVidia driver installed and mostly tamed. I have installed a few packages which I like to use such as Gnome-commander, VLC, VMWare Player etc. So now I decided to pull some of my files from last night's backup to the new /data partition. I am having some issues reading and/or writing from/to /quitelarge. I think this is a clue
[ken@taylor12 quitelarge]$ ls -l
-rw-r--r-- 1 1000 1000 10201597 Jun 10 2010 The Definitive Guide To SQLite (2006).pdf
-rwxrw-r-- 1 1000 1000 471552 Aug 26 2005 TIW_OTHER_TELE.xls
-rwxrw-r-- 1 1000 1000 5937152 Aug 26 2005 TIW_WORKER.xls
drwxr-xr-x 5 1000 1000 12288 Jun 1 06:07 tmp
The files and directories on /quitelarge are owned by UID 1000 which on Ubuntu was my user, ken. On CentOS ken has a UID of 500. These UIDs are assigned during the install/initial user creation and are distro specific and I had not thought about them until now.
So the question is... how can I access /quitelarge from both Ubuntu and CentOS? I do not want to make bulk changes to ownership and permissions in CentOS lest I face the same issue when I go back to Ubuntu.
For the moment I will copy selected files as root from /quitelarge to /data, change the permissions on them and not worry about ever using those files in Ubuntu again. Still, there should be a better way I would hope.