Resizing LVM partitions online in Ubuntu 16.04

Posted on

Resizing paritions is not something I find myself doing very frequently so I tend to forget the procedure. Below is what I did to resize a parition in Ubuntu16.04. This server is a vm running inside esxi.

I’ve already resized the disk in the vmware console from 30 to 100GB. We are now ready to work on the server.

Reisizing the Parition

Here we can see that our Logical Volume is only 24Gb

1
2
3
4
5
6
7
8
9
root@lab:~# df -h
Filesystem                    Size  Used Avail Use% Mounted on
udev                           16G     0   16G   0% /dev
tmpfs                         3.2G   15M  3.2G   1% /run
/dev/mapper/eve--ng--vg-root   24G   15G  6.9G  69% /
tmpfs                          16G     0   16G   0% /dev/shm
tmpfs                         5.0M     0  5.0M   0% /run/lock
tmpfs                          16G     0   16G   0% /sys/fs/cgroup
/dev/sda1                     472M  205M  243M  46% /boot

We set the output to show in bytes and print the sizes of our partitions:

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
root@lab:~# parted
GNU Parted 3.2
Using /dev/sda
Welcome to GNU Parted! Type 'help' to view a list of commands.
(parted) unit b
(parted) print free
Model: VMware Virtual disk (scsi)
Disk /dev/sda: 107374182400B
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Disk Flags:
Number  Start         End            Size          Type      File system  Flags
        32256B        1048575B       1016320B                Free Space
 1      1048576B      511705087B     510656512B    primary   ext2         boot
        511705088B    512752639B     1047552B                Free Space
 2      512752640B    32211206143B   31698453504B  extended
 5      512753664B    32211206143B   31698452480B  logical                lvm
        32211206144B  107374182399B  75162976256B            Free Space

Since our parition is on an extended partition, we need to resize both, the extended (2) and the logical (5) paritions.
We resize these paritions to use the rest of the free space on the disk. This is the value taken from the end column of the last line in the above output.

1
2
3
4
(parted) resizepart 2 107374182399B
(parted) resizepart 5 107374182399B
(parted) quit
Information: You may need to update /etc/fstab.

Next, we need to resize the adjust the size of the physical volume to account for the changes we made in the previous step.

1
root@lab:~# pvresize  /dev/sda5

Now that we have the physical disk resized, we can resize the LVM. You can use lvscan to show the names of the LVM if you are unsure of the names.

1
2
3
root@lab:~# lvscan
  ACTIVE            '/dev/eve-ng-vg/root' [28.52 GiB] inherit
  ACTIVE            '/dev/eve-ng-vg/swap_1' [6.00 GiB] inherit

Here we extend the volume to use 100 percent of the free space on the physical volume.

1
2
3
root@lab:~# lvextend -l +100%FREE /dev/eve-ng-vg/root
  Size of logical volume eve-ng-vg/root changed from 23.52 GiB (6021 extents) to 93.52 GiB (23941 extents).
  Logical volume root successfully resized.

Lastly, we need to tell the partition about the new space so we can use it.

1
2
3
4
5
root@lab:~# resize2fs /dev/eve-ng-vg/root
resize2fs 1.42.13 (17-May-2015)
Filesystem at /dev/eve-ng-vg/root is mounted on /; on-line resizing required
old_desc_blocks = 2, new_desc_blocks = 6
The filesystem on /dev/eve-ng-vg/root is now 24515584 (4k) blocks long.

Verify the new space

1
2
3
4
5
6
7
8
9
root@lab:~# df -h
Filesystem                    Size  Used Avail Use% Mounted on
udev                           16G     0   16G   0% /dev
tmpfs                         3.2G   15M  3.2G   1% /run
/dev/mapper/eve--ng--vg-root   92G   16G   73G  18% /
tmpfs                          16G     0   16G   0% /dev/shm
tmpfs                         5.0M     0  5.0M   0% /run/lock
tmpfs                          16G     0   16G   0% /sys/fs/cgroup
/dev/sda1                     472M  205M  243M  46% /boot