Chapter 4. Importing existing VDO volumes to LVM

You can import a VDO volume that was created by the VDO manager into LVM. As a result, you can manage the volume as a logical volume using the LVM tools.

Note

The import operation is not reversible. After converting an existing VDO volume to LVM, accessing the VDO data is only possible using the LVM commands and the VDO manager no longer controls the volume.

Prerequisites

Procedure

  1. Convert an existing VDO volume created by the VDO manager into a logical volume. In the following command, replace vg-name with the volume group name, lv-name with the logical volume name, and /dev/sdg1 with the VDO device: 

    # lvm_import_vdo --name vg-name/lv-name /dev/sdg1


Convert VDO device "/dev/sdg1" to VDO LV "vg-name/lv-name"? [y|N]: Yes
Stopping VDO vdo-name
Converting VDO vdo-name
     Opening /dev/disk/by-id/scsi-36d094660575ece002291bd67517f677a-part1 exclusively
     Loading the VDO superblock and volume geometry
     Checking the VDO state
     Converting the UDS index
     Converting the VDO
     Conversion completed for '/dev/disk/by-id/scsi-36d094660575ece002291bd67517f677a-part1': VDO is now offset by 2097152 bytes
 Physical volume "/dev/sdg1" successfully created.
 Volume group "vg-name" successfully created
 WARNING: Logical volume vg-name/lv-name_vpool not zeroed.
 Logical volume "lv-name_vpool" created.
 WARNING: Converting logical volume vg-name/lv-name_vpool to VDO pool volume WITHOUT formating.
 WARNING: Using invalid VDO pool data MAY DESTROY YOUR DATA!
 Logical volume "lv-name" created.
 Converted vg-name/lv-name_vpool to VDO pool volume and created virtual vg-name/lv-name VDO volume.
  2. Optional: Create a file system on the VDO LV.
  3. Optional: Mount the LVM-VDO volume. For more information, see Mounting an LVM-VDO volume.

Verification

  • List your LVM devices to verify that importing the VDO volumes to LVM succeeded: 

    # lvs -a -o +devices
  LV                    VG      Attr       LSize  Pool          Origin Data%  Meta%  Move Log Cpy%Sync Convert Devices
  lv-name               vg-name vwi-a-v--- 25.00g lv-name_vpool        0.00                                    lv-name_vpool(0)
  lv-name_vpool         vg-name dwi------- <1.82t                      0.31                                    lv-name_vpool_vdata(0)
  [lv-name_vpool_vdata] vg-name Dwi-ao---- <1.82t                                                              /dev/sdg1(0)

Additional resources

  • lvm_import_vdo(8), lvmvdo(7), and systemd.mount(5) man pages