I manage a pretty standard cPanel server (running CentOS 3.5) and would like to create a couple of new partitions. One would be a partition to store cPanel backups and the second for the MailScanner quarantine.

Since this is a live production server, I won't be creating real paritions, but only what I would describe as "virtual" partitions. Related to this, I previously followed the guide at eth0.us/?q=tmp for securing /tmp and, since I didn't have a separate /tmp partition, only a /tmp directory (as set up by the datacenter), I followed the instructions and successfully created what I call a virtual partition (excuse me if this is not the correct term!).

I'm assuming that I can follow the same process to create further virtual partitions and feel confident in doing so.

However I am curious about where the storage space comes from for new virtual partitions, specifically which real partition the space is borrowed from. More to the point, I'd really like to know how this can be specified. This might seem like a silly question, but I'm still learning and so this is quite new to me.

I can see from the "Show Current Disk Usage" option in WHM that I have the following partitions (or so I believe):

/dev/md2 mounted on /home, with 56GB free
/dev/tmpMnt mounted on /tmp with 730MB free
/dev/md0 mounted on / with 2GB free

When creating these two new virtual paritions, I'd like to borrow the storage space from /home, as this has plenty spare.

Does anyone have any suggestions?