RAID and LVM

From Ece

Incomplete - all the parts are here, but it is incoherent

In this example, we will take a PC with one drive, add another drive, create a RAID 1 array between the drives and use LVM for the mounts that we can. We will then migrate the data from the original drive to the RAID array.

• Install the second drive in the PC.
• Run fdisk and set the partitions for the second drive. In this example we will create two partitions. The first partition will hold /boot (~100MB) and the second partition will encompass the rest of the drive. An LVM, which contains the swap and root volumes, will be created on the second partition. Make sure to toggle each partition type to "Linux raid auto" (fd). We separate the /boot partition from the rest of the LVMs to make it easier for Linux to boot. Some can't boot for LVMs.
• Create a RAID 1 array on the first and second partitions.

  mdadm -C /dev/md0 --level=1 --raid-devices=2 missing /dev/hdb1 --auto=yes

  mdadm -C /dev/md1 --level=1 --raid-devices=2 missing /dev/hdb2 --auto=yes

• Now we create the LVM (physical volume and volume group) on the second RAID partition.

  pvcreate /dev/md1

  vgcreate VolGroup01 /dev/md1

• After the LVM volume group is created, we create a logical volume for swap (2GB) and root (120GB).

  lvcreate -L2000 -nswap VolGroup01

  lvcreate -L120000 -nroot VolGroup01

• Make a swap partition.

  mkswap /dev/VolGroup01/swap

• Create a filesystem on the root volume. We chose to use ext3.

  mkfs.ext3 /dev/VolGroup01/root

  mkfs.ext3 /dev/md0

setup grub edit fstab

mkinitrd --preload raid1 /boot/initrd-`uname -r`.img `uname -r`

mount both /dev/md0 and /dev/VolGroup01/root

find / -mount -depth -print | cpio -pdmv /PATH_TO_ROOT_MOUNT

find /boot -mount -depth -print | cpio -pdmv /PATH_TO_BOOT_MOUNT

chroot to LVM root volume and run grub-install

reboot

mdadm /dev/md0 --add /dev/hda1

mdadm /dev/md1 --add /dev/hda2