3.4. Creating and mounting an LVM-VDO volume

Procedure

1. Create the LVM-VDO:

   # lvcreate --type vdo \
              --name vdo1 \
              --size 1T \
              --virtualsize 10T \
              <vg_name>

   Replace 1T with the physical size. If the physical size is larger than 16 TiB, add the following option to increase the slab size on the volume to 32 GiB:

   --vdosettings 'vdo_slab_size_mb=32768'

   If you use the default slab size of 2 GiB on a physical size larger than 16 TiB, the lvcreate command fails with the following error:

   ERROR - vdoformat: formatVDO failed on '/dev/<device>': VDO Status: Exceeds maximum number of slabs supported

   Replace 10T with the logical storage that the LVM-VDO will present.

   Replace <vg_name> with the name of an existing LVM volume group where you want to place the LVM-VDO.

   重要

   If creating the LVM-VDO volume fails, use lvremove <vg_name> to remove the volume. Depending on the reason of the failure, you might also need to add two force options (-ff).

2. Create a file system on the LVM-VDO:

   • For the XFS file system:

     # mkfs.xfs -K /dev/<vg_name>/<vdo_name>

   • For the ext4 file system:

     # mkfs.ext4 -E nodiscard /dev/<vg_name>/<vdo_name>

3. Mount the file system on the LVM-VDO volume:

   • To mount the file system persistently, add the following line to the /etc/fstab file:

     /dev/<vg_name>/<vdo_name> <mount_point> <file_system_type> defaults 0 0

     Replace <file_system_type> with your file system, such as xfs or ext4.

   • To mount the file system manually, use the mount command:

     # mount /dev/<vg_name>/<vdo_name> <mount_point>

     If the LVM-VDO volume is located on a block device that requires network, such as iSCSI, add the _netdev mount option. For iSCSI and other block devices requiring network, see the systemd.mount(5) man page for information about the _netdev mount option.