Q: How do I partition a hardware RAID disk?

We have the following partition table:

/dev/rd/c0d0p1 * 1 751 153032 83 Linux native
/dev/rd/c0d0p2 752 816 133120 82 Linux swap
/dev/rd/c0d0p3 817 881 133120 82 Linux swap
/dev/rd/c0d0p4 882 17366 33761280 83 Linux native

I want to slice up the giant partition (/dev/rd/c0d0p4). So, I deleted the partition and created an extended partition (using fdisk) of the same size. (I made the proper adjustments in /etc/fstab.) I then added 5 smaller partitions, and left much of the disk free (for later).

After writing and exiting fdisk, I get the following message:

The partition table has been altered!

Calling ioctl() to re-read partition table.
Syncing disks.
Re-read table failed with error 16: Device or resource busy.
Reboot your system to ensure the partition table is updated.
------------NEW PARTITION TABLE----------------
After rebooting, the new partition tables are there.
-- Device Boot Start End Blocks Id System
/dev/rd/c0d0p1 * 1 751 1538032 83 Linux native
/dev/rd/c0d0p2 752 816 133120 82 Linux swap
/dev/rd/c0d0p3 817 881 133120 82 Linux swap
/dev/rd/c0d0p4 882 17366 33761280 5 Extended
/dev/rd/c0d0p5 882 1922 2131952 83 Linux native
/dev/rd/c0d0p6 1923 2408 995312 83 Linux native
/dev/rd/c0d0p7 2409 2981 1173488 83 Linux native
/dev/rd/c0d0p8 2982 4228 2553840 83 Linux native
/dev/rd/c0d0p9 4229 6324 4292592 83 Linux native
-----------------------------------------------
When I try to mount one of the partitions I get:
[root@cuba /root]# mount /dev/rd/c0d0p5 /mnt/tmp
mount: you must specify the filesystem type
[root@cuba /root]# mount -t ext2 /dev/rd/c0d0p5 /mnt/tmp
mount: wrong fs type, bad option, bad superblock on /dev/rd/c0d0p5,
or too many mounted file systems
----------------DEV/RD LIST---------------------
Also I don't see all of my new partitions in the /dev/rd directory.
[root@cuba /root]# ls /dev/rd/c0d0*
/dev/rd/c0d0
/dev/rd/c0d0p2 /dev/rd/c0d0p4 /dev/rd/c0d0p6
/dev/rd/c0d0p1 /dev/rd/c0d0p3
/dev/rd/c0d0p5 /dev/rd/c0d0p7

A: Two problems:

1) You have to reboot after altering the partition table, if you have any partitions on that drive mounted.

2) The Mylex DAC960 can have partitions up to only 7 (1-7) on a single logical disk. Anything more would require reconfiguring the RAID array. Which would then require reinstallation.