How to resize hard drive on Linux systems with LVM

Question

The free disk space is exceeded on the server. Disk size for the server has been extended from the hardware node side of the virtualization, however these changes are not being reflected from the inside of the virtual machine.
How to extend disk size inside of the virtual machine that uses LVM?

Answer

Warning: The following article is applicable only for the systems that use LVM. Before applying the steps below, create a backup of the virtual machine.

Note: That such task is not-Plesk related and is not covered by Plesk Technical Support. If you are not familiar with Linux system administering and would like our professionals to handle this task, contact Professional Service team using the following link:
https://www.plesk.com/professional-services/

1. Connect to the server using SSH

2. Make sure that the server uses LVM:

   • The similar output will be returned if LVM is present:

     # lvs
     LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
     root centos -wi-ao---- <8.00g
     swap centos -wi-ao---- 1.00g

     Note: centos here is the name of the logical group. It will be used in the further steps

   • The similar output will be returned if LVM is not present:

     # lvs
     -bash: lvs: command not found

     # lvdisplay -v
     No volume groups found.

     Warning: In this case, solution from the article cannot be applied, as the server does not use LVM.

3. Start cfdisk to get information about current partition schema:

   # cfdisk

   Note: Unallocated disk space will have Free Space FS Type. This space can be used for creation of a partition and for further LVM extension

   

4. Select unallocated disk space using arrow buttons and create a new partition by clicking on the [ New ] button:

   

5. Follow the wizard to create a Primary partition and its size. Primary type is selected by default, and the default size corresponds to the free disk space size

6. Click on [ Write ] and then [ Quit ] to confirm create and apply changes to the hard drive partition table:

   

   Note: The name of the new partition may vary, in this case it is sda3. It will be used in the further steps

7. Run partprobe to load partition changes in userspace:

   # partprobe

8. Once new partition table is loaded, it is possible to add a new volume to the logical group using its name:

   # vgextend centos /dev/sda3
   Physical volume "/dev/sda3" successfully created
   Volume group "centos" successfully extended

   Note: Volume and logical group names may vary, in this case it is centos and sda3. Refer to step 6 and command cfdisk to get volume name and to step 2 and command vgdisplay to get volume group name

9. Then it is possible to extend logical volume of root directory to add all unused space available in the volume group:

   # lvdisplay | grep 'LV Path'
   LV Path /dev/centos/root
   LV Path /dev/centos/swap

   # ls -la /dev/centos/root
   lrwxrwxrwx. 1 root root 7 Aug 28 21:14 /dev/centos/root -> ../dm-0

   # lsblk /dev/dm-0
   NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
   centos-root 253:0 0 23G 0 lvm /

   Note: Since /dev/centos/root is mounted on the /, as displayed above, it should be resized. Logical volume name may vary

   # lvresize -l +100%FREE --resizefs /dev/centos/root

10. Extend the partition located on the logical volume:

    Note: To determine file system, run file -sL /dev/centos/root

    For XFS:

    1. Install required packages:

       • For .rpm-based OS (RHEL, CentOS, CloudLinux)

         # yum install -y xfsprogs

       • For .deb-based OS (Debian, Ubuntu)

         # apt install -y xfsprogs

    2. Grow partition:

       # xfs_growfs -d /dev/centos/root

    For ext2/ext3/ext4

    1. Install required packages:

       • For .rpm-based OS (RHEL, CentOS, CloudLinux)

         # yum install -y e2fsprogs

       • For .deb-based OS (Debian, Ubuntu)

         # apt install -y e2fsprogs

    2. Grow partition:

       # resize2fs /dev/centos/root

11. Check that the disk space has been extended:

    # df -h

Alternatively, it is possible to decrease the /home partition and increase the / partition using the utilities lvreduce ( https://linux.die.net/man/8/lvreduce ) and lvextend ( https://linux.die.net/man/8/lvextend ).
This may be required on a default CentOS installations where only 50 GB are allocated for the / partition and all Plesk domains, mail, backups, and databases are stored in the /var directory, which in this case is located inside the / partition.