Adding a disk to a RAID array

I am not sure where to start so I will just jump right in.  Up until
last week I had the manual for the SCSI card in my hand and now it has
managed to disappear.  I am still looking for it, although I have found
a generic one from Adaptec that I have printed out and will go through.
Hopefully I will be able to find out what I need to know concerning the
hardware recognition of a new drive in the array.

Hardware info:
DPT (bought out by Adaptec) PM2654 I20 BIOS SmartRAID V controller card,
firmware updated last April
3   SCSI Hard drives  36gb Segate

Here's the problem:

I have a SCSI hardware RAID array of 3 drives.  Space is running out on
the data partition of the array and I need to add another 36gb drive to
the array. I think that all I need to do for the drive to be seen by the
hardware is to install the drive and boot up however, I am still looking
in to that.  Here is the partition information:
                   start        end     mgb      part type     mounted
/dev/sda
   - sda1         1            9        71        ext3            boot
   - sda2        10         270    2047      Linux-swap
   - sda3       271        336     518       ext3            tmp
   - sda4      337        8924   67366    Extended
       - sda5  337         859    4103      ext3
       - sda6  860        8924   6324      ext3            data

I want to add the new drive space to the end of sda6 and into the
mounted data partition but I have not been able to find out any
information on how to do this.  I have looked through a stack of books,
asked those in the "know" here at work and no one seems to be able to
tell me how to do it.  I know that I will have to back every thing up in
the data partition before doing this.  I also know that I have to do
something in fdisk.  I once did something like this to a non RAIDed
Alpha Ultrex system about 6yrs ago but have no idea of how to proceeded
here.  I am trying not to have to reinstall the entire system just to
install a new drive.

Assistance is greatly appreciated.

Elizabeth R. E. Martin
Network Support Specialist
UT-Houston Medical School

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