There are a few short steps to adding more drive space to Linux:
In this example we will fdisk the first logical drive attached to our 2nd array controller. Also, the partition we create in this example is partition #5 (c1d0p5):
fdisk the new drive
fdisk /dev/ida/c1d0
Make a new partition using fdisk
format the new partition using mkfs
mkfs /dev/ida/c1d0p5
Note, if you will be storing lots of small files, you may need to increase the inode count. You do this when you format the drive. The default count of inodes will be good for most people.
Make a new directory to mount your new space to
mkdir /newspace
Note: If moving a current filesystem over to this new space, you will need to first mount the new space to a temporary mount point, move all the contents to it, then unmount that temporary mount point, and finally add an entry in /etc/fstab so it will mount automatically on bootup.
Have the new drive mount automatically
vi /etc/fstab
make a copy of an existing line
change this new line to match your partition number
Test that your partition mounts ok according to the changes you made in /etc/fstab