linux luks lvm devops

Add disks to a setup with a LUKS container on a LVM volume without losing data

Need to expand disk space on a system using LUKS encryption over LVM? Here’s how to do it without losing any data.

Prerequisites: Make sure you have backups before proceeding.

Setup:

  • Physical disks: sde, sdf (new disks to add)
  • Volume group: vg-01
  • Logical volume: lvdata
  • LUKS container: luksdata

Steps

First, create physical volumes on the new disks and extend the volume group:

pvcreate /dev/sde /dev/sdf
vgextend vg-01 /dev/sde /dev/sdf

Resize the logical volume to use all available free space:

lvresize -l +100%FREE /dev/vg-01/lvdata

Open the LUKS container and resize it:

cryptsetup luksOpen /dev/vg-01/lvdata luksdata
cryptsetup resize luksdata

Mount and grow the filesystem:

mount -t xfs /dev/mapper/luksdata /mnt/data
xfs_growfs /dev/mapper/luksdata

Note: I’m using XFS in this example. If you’re using an ext-based filesystem, you would use resize2fs instead of xfs_growfs.

That’s it! The commands above successfully expanded my storage without any data loss.