====== How to migrate Linux x86/ppc64le on another storage ======

Migrate standard RHEL installation from one hard disk to another

==== For x86_64 ====

Scenario:
<code>
vda -> Old Disk
vdb -> New Disk
centos -> root volume group
</code>

Partitioning:
<cli prompt='#'>
# df -h
Filesystem               Size  Used Avail Use% Mounted on
/dev/mapper/centos-root   18G  983M   17G   6% /
devtmpfs                 487M     0  487M   0% /dev
tmpfs                    497M     0  497M   0% /dev/shm
tmpfs                    497M  6.7M  490M   2% /run
tmpfs                    497M     0  497M   0% /sys/fs/cgroup
/dev/vda1                497M  164M  333M  33% /boot
tmpfs                    100M     0  100M   0% /run/user/0
tmpfs                    100M     0  100M   0% /run/user/1000
</cli>

<cli prompt='#'>
# fdisk -l
   Device Boot      Start         End      Blocks   Id  System
/dev/vda1   *        2048     1026047      512000   83  Linux
/dev/vda2         1026048    41943039    20458496   8e  Linux LVM
</cli>

Steps:

Clean yum cache:
<cli prompt='#'>
# yum clean all
</cli>

Clone partitioning scheme:
<cli prompt='#'>
# sfdisk -d /dev/vda | sfdisk --force /dev/vdb
</cli>

Suppress current multipathing
<cli prompt='#'>
# mv /etc/multipath/* /tmp
</cli>

Move Logical Volume to new disk:
<cli prompt='#'>
# pvcreate /dev/vdb2
# vgextend centos /dev/vdb2
# pvmove /dev/vda2
# vgreduce centos /dev/vda2
# pvremove /dev/vda2
</cli>

Clone /boot:
<cli prompt='#'>
# umount /boot/
# dd if=/dev/vda1 of=/dev/vdb1 bs=512 conv=noerror,sync
# mount /boot
</cli>

Copy boot sector:
<cli prompt='#'>
# dd if=/dev/vda of=/dev/vdb bs=1 count=512
</cli>

**If MBR is used**
Install GRUB in new disk:
<cli prompt='#'>
# grub2-install /dev/vdb
</cli>
check the file : /boot/grub2/device.map

**If EFI is used**
Copy the efi boot manager, the label must be different to previous one
<cli prompt='#'>
# efibootmgr -c --disk /dev/sdc --part 1 -L "Red Hat Enterprise Linux 7.3"
</cli>

Sync changes:
<cli prompt='#'>
# sync
</cli>

Reboot your physical or virtual machine, please make sure that your new disk is the default boot device or remove old disk but don't delete data, can be useful in a rollback situation.

==== For POWER ====

Scenario:
<code>
sda -> Old Disk
sdb -> New Disk
ca -> root volume group
</code>

Partitioning:
<cli prompt='#'>
# df -h
Filesystem           Size  Used Avail Use% Mounted on
/dev/mapper/ca-root   28G  1.1G   27G   4% /
devtmpfs             449M     0  449M   0% /dev
tmpfs                495M     0  495M   0% /dev/shm
tmpfs                495M   12M  484M   3% /run
tmpfs                495M     0  495M   0% /sys/fs/cgroup
/dev/sda2            497M  143M  354M  29% /boot
tmpfs                 99M     0   99M   0% /run/user/0
</cli>
<cli prompt='#'>
# fdisk -l
  Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *        2048       10239        4096   41  PPC PReP Boot
/dev/sda2           10240     1034239      512000   83  Linux
/dev/sda3         1034240    62914559    30940160   8e  Linux LVM
</cli>

Steps:

Clean yum cache:
<cli prompt='#'>
# yum clean all
</cli>

Clone partitioning scheme:
<cli prompt='#'>
# sfdisk -d /dev/sda | sfdisk --force /dev/sdb
</cli>

Move Logical Volume to new disk:
<cli prompt='#'>
# pvcreate /dev/sdb3
# vgextend centos /dev/sdb3
# pvmove /dev/sda3
# vgreduce centos /dev/sda3
# pvremove /dev/sda3
</cli>

Clone PPC PReP Boot partition:
<cli prompt='#'>
# dd if=/dev/sda1 of=/dev/sdb1 bs=512 conv=noerror,sync
</cli>

Clone /boot:
<cli prompt='#'>
# umount /boot/
# dd if=/dev/sda2 of=/dev/sdb2 bs=512 conv=noerror,sync
# mount /boot
</cli>

Copy boot sector:
<cli prompt='#'>
# dd if=/dev/sda of=/dev/sdb bs=1 count=512
</cli>

Install GRUB in new disk:
<cli prompt='#'>
# grub2-install /dev/sdb
</cli>
check the file : /boot/grub2/device.map

If you receive this message: grub2-install: error: the chosen partition is not a PReP partition. maybe you can try with:
<cli prompt='#'>
# grub2-install /dev/sdb1
</cli>

Sync changes:
<cli prompt='#'>
# sync
</cli>

Reboot your physical or virtual machine, please make sure that your new disk is the default boot device or remove old disk but don't delete data, can be useful in a rollback situation.