Expanding the logical volume is extremely easy, it takes very few steps and can be done online without unmounting a certain logical volume.
The main purpose of LVM is flexible disk management, which allows you to easily resize, extend and reduce the logical volume size when you need it.
If you are new to Logical Volume Management (LVM), I suggest you start with our previous article.
Expanding the logical volume involves the below steps.
- Check if you have sufficient unallocated disk space in the volume group where the LV was residing.
- If yes, you can use that space to extend the logical volume.
- If not, add new disks or LUNs to your system.
- Convert a physical disk as a physical volume (PV).
- Extend the Volume Group
- Increase the logical Volume
- Grow the filesystem
- Check the extended filesystem size
How to Create LVM Physical Volumes
Create LVM physical volumes with the pvcreate command.
Once the disk is detected in the OS, use the pvcreate command to initialize the LVM PV (Physical Volumes).
# pvcreate /dev/sdc Physical volume "/dev/sdc" successfully created
Make a note:
- The above command erases any data on the given disk /dev/sdc.
- Physical disk can be added directly into the LVM PV instead of the disk partition.
Use the pvdisplay command to display the PVs you have created.
# pvdisplay /dev/sdc "/dev/sdc" is a new physical volume of "10.00 GiB" --- NEW Physical volume --- PV Name /dev/sdc VG Name PV Size 10.00 GiB Allocatable NO PE Size 0 Total PE 0 Free PE 0 Allocated PE 0 PV UUID 69d9dd18-36be-4631-9ebb-78f05fe3217f
How to Extend the Volume Group
Use the following command to add a new physical volume to the existing volume group.
# vgextend vg01 /dev/sdc Volume group "vg01" successfully extended
Use the vgdisplay command to display the PVs you have created.
# vgdisplay vg01 --- Volume group --- VG Name vg01 System ID Format lvm2 Metadata Areas 2 Metadata Sequence No 1 VG Access read/write VG Status resizable MAX LV 0 Cur LV 0 Open LV 0 Max PV 0 Cur PV 2 Act PV 2 VG Size 14.99 GiB PE Size 4.00 MiB Total PE 3840 Alloc PE / Size 1280 / 4.99 Free PE / Size 2560 / 9.99 GiB VG UUID d17e3c31-e2c9-4f11-809c-94a549bc43b7
How to Extend the Logical Volume
Use the following command to increase the existing logical volume.
Common syntax for logical volume extension (lvextend).
lvextend [Additional space to be added] [Existing Logical Volume Name]
Use the below command to increase the existing logical volume additionally to 10GB.
# lvextend -L +10G /dev/mapper/vg01-lv002 Rounding size to boundary between physical extents: 5.90 GiB Size of logical volume vg01/lv002 changed from 5.00 GiB (1280 extents) to 15.00 GiB (3840 extents). Logical volume var successfully resized
To extend logical volume using PE size’s.
# lvextend -l +2560 /dev/mapper/vg01-lv002
To extend the logical volume using percentage (%), use the following command.
# lvextend -l +40%FREE /dev/mapper/vg01-lv002
Now, the logical volume is extended and you need to resize the file system to extend the space inside the logical volume.
For an ext3 and ext4 based file system, run the following command.
# resize2fs /dev/mapper/vg01-lv002
For the xfs file system, use the following command.
# xfs_growfs /dev/mapper/vg01-lv002
Use the df command to view the file system size.
# df -h /lvmtest1 Filesystem Size Used Avail Use% Mounted on /dev/mapper/vg01-lv002 15360M 34M 15326M 4% /lvmtest1