When you add a new device to the server, you need to partition it up. You only need two of them. This will make a 1GB device for /boot and use the rest for LVM.
# fdisk /dev/<new_dev> Command: n Primary?: p Number: 1 Start: <enter> End: 1G Command: n Primary?: p Number: 2 Start: <enter> End: <enter>
Install LVM on the <new_dev>2. This will make a 1G swap and give the rest to /. This will change depending on where you are. You might need to make more LVs if you want /var or /usr to be on different drives.
# pvcreate /dev/<new_dev>2 # vgcreate vg_root /dev/<new_dev>2 # lvcreate -n lv_swap vg_root -L 1G # lvcreate -n lv_root vg_root -l 100%FREE
Create the file-systems for /boot and / (and any other devices you may have created), and enable swap
# mkfs.ext4 /dev/<new_dev>1 # mkfs.ext4 /dev/vg_root/lv_root # mkswap /dev/vg_root/lv_swap
Set up a temporary environment under /mnt and copy the files (be sure to create any other mounts you need and mount the OS related LVs there)
# mount /dev/vg_root/lv_root /mnt # mkdir /mnt/boot # mkdir /mnt/proc # mkdir /mnt/sys # mkdir /mnt/dev # mount /dev/<new_dev>1 /mnt/boot # cp -vax / /mnt/ # cp -vax /boot /mnt/
Go into the new temporary setting. This will trick your console into thinking you are now in the new environment.
# mount -o bind /proc /mnt/proc # mount -o bind /dev /mnt/dev # mount -o bind /sys /mnt/sys # choot /mnt
Rebuild the initial ramdisk.
# dracut -f
Update the “kernel” line in /boot/grub/grub.conf file with the following.
* set the root= parameter to /dev/vg_root/lv_root * remove rd_NO_LVM * add rd_LVM_LV=vg_root/lv_root
Make a file under /boot so that grub can find it.
# touch /boot/testfile
Type grub and look for the file. This will give you a value of (hdX,X).
grub> find /testfile
Use the value from the above command and reinstall grub.
grub> root (hdX,X)
grub> setup (hdX)
grub> quit
Update your /etc/fstab with the new locations to your devices.
Turn off the computer and get rid of the old disks. Start up again and make sure everything works right.
