topic Re: Mirror boot disk on RHEL4 in Operating System - Linux

Mirror boot disk on RHEL4

Geetha_1 — Thu, 08 Feb 2007 13:42:56 GMT

How do I mirror the boot disk on an Itanium server (rx4640)? Can someone show me the exact steps involved? I have used Mirror/UX for boot disk mirroring on hp-ux. Is there something similar to this available for RHEL4?
Thanks.
Geetha.

Re: Mirror boot disk on RHEL4

Ivan Ferreira — Thu, 08 Feb 2007 14:05:30 GMT

During installation, mirror everything except the EFI partition (you cannot do it during installation because is vfat). But in the second disk, you need to leave a partition equal to the EFI partition on the first disk.

After the installation, you need to save the contents of the /boot/efi using a backup tool. Then you need to manually create the raid (using raidtab o mdadm), using the partitions (the actual boot/efi and the reserved on the second disk), create the vfat filesystem on it and then restore the backup. (See the howtos)

Then you can add the second disk as an option on the EFI shell.

Is not an easy task, but can be done.

Basic steps after installation could be:

tar cvf /root/efiboot.tar /boot/efi
umount /boot/efi
parted /dev/sda
Set the boot partition as RAID
parted /dev/sdb
Set the boot partition as RAID
mdadm â -create -â verbose /dev/md â -level=1 -â raid-devices=2 /dev/sda1
/dev/sdb1
mkfs -t vfat /dev/md
mount -t vfat /dev/md /boot/efi
cd /
tar xvf /root/efiboot.tar
Edit /etc/fstab and replace /dev/sda1 on /boot/efi by /dev/md.

Re: Mirror boot disk on RHEL4

Geetha_1 — Thu, 08 Feb 2007 14:48:42 GMT

Ivan,
As I am new to the RHEL - some of my questions may be very basic. I don't remember seeing an option for mirroring partitions other than /boot/efi during installation? Where is the option? When I create partitions such as /usr, /var /home etc - should I choose type as RAID?
Thanks.

Re: Mirror boot disk on RHEL4

Ivan Ferreira — Thu, 08 Feb 2007 16:43:34 GMT

You must create one partition on each disk and then set the partition type as Software RAID. Then use the "RAID" button (Next to the LVM button) to create the array between the partitions.

Re: Mirror boot disk on RHEL4

Geetha_1 — Fri, 09 Feb 2007 11:14:25 GMT

Ivan,
Thanks!