RE: Adding a disk to a RAID array

>From what you are stating it seems that the RAID is implemented in HW. As a
result the OS does not see anything. All the RAID stuff shows up as single
drive. The point that you have to back-up all the data in the data partition
is that the partition during the reconfiguration of the controller will be
deleted and recreated. Say you have two drives and later it will have three
drives. The drive will seem the same to OS. The only difference will be the
space it contains. At this point you will restore all the data from backup
and the partition will seem to be the same as before but with more free
space.

Sincerely
Mr. Olsi Lulani


-----Original Message-----
From: Elizabeth R Martin [mailto:[email protected]] 
Sent: Friday, March 14, 2003 4:01 PM
To: Red Hat 7.2
Subject: 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