On Fri, Jun 3, 2011 at 6:50 AM, James Holland <[log in to unmask]> wrote:
> So, just mount your 4TB on /home. Stick it in the fstab as LABEL=/home /home
> ext3 defaults 1 2

Whoaa!!! Slow down there, pardner!

You'll want to select a reasonable chunk of that 4 TB, perhaps all of
it, as the new /home partition. Mount it temporarily, then *backup the
contents of /home to the new  mountpoint*. When ready, announce some
downtime, get people off the system, move aside /home, do a finaly
mirroring, verify that nothing is writing to the old /home with
"lsof", then remount the new partition as /home. Keep the old /home
around, say as "/home.old", for  a while foe people to settle in.

If you can schedule time, try to do this in single user mode, it's a
lot safer. Simply slapping new disk space on top of your old /home
will hide the old /home directories, and you won't be able to *access*
it to do copies. Worse, processes can still be writing to the old
files *under* your new mount point, and chaos can ensue without some
elementary caution.