grow-root-partition.md

How to grow root partition (ubuntu server, minimal)

The basic scene. You messed up with your Ubuntu Server Minimal Installation running on a virtual machine. / is full. You extend the disk size on your hypervisor. What next?

Check what you have

First let's check situation. What disk is full?

> df -h
Filesystem                             Size  Used Avail Use% Mounted on
...
/dev/vda2                              9.3G  9.2G     0 100% /
...
/dev/vda1                              537M  6.1M  531M   2% /boot/efi

/dev/vda seems to be full. Root partition is on /dev/vda2. Has the disk /dev/vda more unallocated space available?

> fdisk -l

GPT PMBR size mismatch (20971519 != 41943039) will be corrected by write.
The backup GPT table is not on the end of the device.
Disk /dev/vda: 20 GiB, 21474836480 bytes, 41943040 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: gpt
Disk identifier: 82317E4E-AD48-4CC6-94BE-8102E95D5855

Device       Start      End  Sectors  Size Type
/dev/vda1     2048  1103871  1101824  538M EFI System
/dev/vda2  1103872 20969471 19865600  9.5G Linux filesystem

Fdisk indicates that /dev/vda2 is not filling the entire disk. 20th million sector is the last one, but the disk has 41 million sectors available.

Extend your volume and filesystem

Luckily, even the minimal installation has the required tools.

> sudo growpart /dev/vda 2     # <---- Note the space between vda and 2.
CHANGED: partition=2 start=1103872 old: size=19865600 end=20969472 new: size=40839135 end=41943007
> sudo resize2fs /dev/vda2
resize2fs 1.46.5 (30-Dec-2021)
Filesystem at /dev/vda2 is mounted on /; on-line resizing required
old_desc_blocks = 2, new_desc_blocks = 3
The filesystem on /dev/vda2 is now 5104891 (4k) blocks long.
> sudo reboot                  # <---- Not actually necessary, but do it anyway.