Upgrading to larger hard disks - How do I set about it.
 

I run RedHat Enterprise Server with the operating system installed on mirrored disks (hardware mirroring) and the data on a raid system giving me 380 Gig but I now want to upgrade the raid system to 1.4 TB.

I also run Fedora 8 which has two SATA disks, one 80 Gig (with operating system) and the other 500 Gig (data). Currently I use rsync to update the data from the RedHat 380 Gig to the Fedora 500 Gig. I need to increase the size of the disk on the fedora machine to match that of the RedHat machine.

RedHat.
I am uncertain of the steps I need to follow to accomplish what I want to do. I have the following in mind:
1. Backup (to tape) what is on the 380 Gig raid.
2. Unmount the raid system (I have the device and mount point).
3. Install the larger disk and set up the hardware raid.
4. Mount the raid system using the device and mount point in (2) above.
5. MUST I FORMAT THE RAID AT THIS POINT (AS WOULD HAPPEN IN THE INSTALL PROCESS) ? (HOW ?)
6. Restore (from tape) the data backed up.

Fedora. What steps should be followed for this machine to move to a larger disks or perhaps just add disks for the data.

Hi. It seems you have to format the filesystem. More you have to label the new drive first. So the steps are:

fdisk /dev/<raid device>
press 'p' to print the data
press 'n' to create new partition
press 'w' to write the data to the harddrive
press 'q' to quit.

'h' stands for 'help' ;-)

The problem with fdisk is that it's rather user-unfriendly and (secondly) it can't create a partition larger than 2TB
There is a program called 'cfdisk' which acts like fdisk but has nicer user interface.
The only software I know that creates partitions larger than 2tb is 'parted' or 'gparted' for its gui version.

Now you have to format the partition.

For ext3 partition use:
mkfs.ext3 /dev/<partition device>

For jfs partition use:
mkfs.jfs /dev/<partition device>

ext3 is a standard partition format used in linux.
jfs is much more robust and has almost every feature that ext3 does. You may want to read about the differences, pros and cons. There are some articles on the web.

There is also xfs filesystem worth mentioning. It also performs better than ext3, especially in case of really large files.

cheers,
lukost

lukost, thanks a million !
I¨ll follow the process and let you know the results.

Hi lukost.
I eventually got around to attempting to execute the process as you described it. I didn't get past the "umount".

I typed "umount /db4" and got a reply of
"umount: /db4: device is busy"
"umount: /db4: device is busy".

Then I tried "umount -f /db4" and got a reply of
"umount2: Device or resource busy"
"umount: /db4: device is busy"

I've tried stopping a whole lot of services and killed processes that were left when folk didn't log out but the umount produces the same result.
Any suggestions ?

I also tried the umount on the Fedora machine's 500gig disk.
The umount is executed but when I reboot the machine a find that the "umount"ed disk is mounted. Is this normal ? I rebooted expecting to see that the 500gig disk was no longer available.