====== Migrate data drives ======
This guide shows how to migrate data drives from an old server to a new machine. This works when the old server is still accessible. My setup is 2 HDD -> RAID 1 -> LVM2 -> LUKS -> ext4 so it is very important to do all the steps in the correct sequence as outlined below. In my setup all data is mounted as ''/home'', the volume group is ''vg_data'', the logical volume ''lv_home''.

In my configuration the crypt container and mounting of the filesystem are handled in a batch file. This is not reflected here, and I have also not included instructions how to mount the encrypted container to a mount point.

===== Old Server =====
==== Preparation ====
  - Copy ''/etc/mdadm/mdadm.conf'' to external storage
  - Copy ''/root'' to external storage
  - Copy ''/etc'' to external storage

==== File System & LUKS ====
  - Unmount /home:<file>sudo umount /home</file>You might need to force unmount
  - Close the LUKS container:<code>sudo cryptsetup luksClose vg_data-lv_home_crypt</code>
  - Alternatively, instead of step 2 & 3, you may want to reboot the machine without providing the encryption password to avoid LUKS opening the encrypted container.

==== LVM2 ====
  - Use ''vgdisplay'' and ''lvdisplay'' to understand your LVM configuration
  - Deactivate logical volume(s): ''lvchange -an /dev/vg_data/lv_home''
  - Deactivate volume group: ''vgchange -an vg_data''
  - Export the volume group: ''vgexport vg_data''

===== New Server =====
  - Create a temporary ''/home'' mount point
  - Install RAID, LVM, and cryptsetup into the new server
  - Do not connect the data drives yet

==== RAID ====
  - Copy the RAID configuration (''mdadm.conf'') from the old server to the new server
  - Shut down the system, connect the data drives, then reboot the system
  - Check with ''lsblk''

==== LVM2 ====
  - Run ''pvscan'' to list the exported volume group(s)
  - Import the volume group: ''vgimport vg_data''
  - Activate the volume group: ''vgchange -ay vg_data''
  - Activate the volume(s): ''lvchange -ay /dev/vg_data/lv_home''

==== File System & LUKS ====
  - Open the LUKS container and provide the passphrase:<code>sudo cryptsetup luksOpen /dev/mapper/vg_data-lv_home vg_data-lv_home_crypt</code>
  - Mount the filesystem:<code>mount /dev/mapper/vg_data-lv_home_crypt /home</code>
  - Modify ''fstab'' and give the temporary ''/home'' directory a new mount point
  - Run ''update-initramfs -u'' 

===== Links =====
  * [[https://docs.redhat.com/en/documentation/red_hat_enterprise_linux/4/html/cluster_logical_volume_manager/vg_move|Moving a Volume Group to Another System]]
  * [[https://askubuntu.com/questions/529843/move-raid-1-array-to-new-system/529845#answers-header|Move RAID 1 Array to new system]]