Rytis Grincevičius

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Extending Amazon AWS EC2 instance volumes

Step-by-step tutorial on how to extend EC2 instance volumes with zero downtime.

2 min read

I did write this tutorial for my team's wiki some time ago and thought that I could share it here. Skip to the end of the article to see a short version :)

Long version

Open Elastic Block Storage -> Volumes in EC2 instances. Select the volume you want to extend and click Actions -> Modify Volume.

Enter a new volume size in the input field, and save it.

Connect to EC2 instance using your terminal.

Check current volume size:

rytis@aws:~$ lsblk
NAME        MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
nvme0n1     259:0    0  40G  0 disk 
└─nvme0n1p1 259:1    0  30G  0 part /

Extend partition on volume:

rytis@aws:~$ sudo growpart /dev/nvme0n1 1
CHANGED: partition=1 start=2048 old: size=62912479 end=62914527 new: size=83883999,end=838860477

Confirm that the new partition size is updated:

rytis@aws:~$ lsblk
NAME        MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
nvme0n1     259:0    0  40G  0 disk 
└─nvme0n1p1 259:1    0  40G  0 part /

Check on filesystems type and size:

rytis@aws:~$ df -Th
Filesystem     Type      Size  Used Avail Use% Mounted on
udev           devtmpfs  3.8G     0  3.8G   0% /dev
tmpfs          tmpfs     764M   81M  683M  11% /run
/dev/nvme0n1p1 ext4       30G   26G  3.5G  89% /
tmpfs          tmpfs     3.8G  8.0K  3.8G   1% /dev/shm
tmpfs          tmpfs     5.0M     0  5.0M   0% /run/lock
tmpfs          tmpfs     3.8G     0  3.8G   0% /sys/fs/cgroup
tmpfs          tmpfs     764M     0  764M   0% /run/user/1002

A. If filesystem type is ext2, ext3 or ext4:

rytis@aws:~$ sudo resize2fs /dev/nvme0n1p1
resize2fs 1.42.13 (17-May-2015)
Filesystem at /dev/nvme0n1p1 is mounted on /; on-line resizing required
old_desc_blocks = 2, new_desc_blocks = 3
The filesystem on /dev/nvme0n1p1 is now 10485499 (4k) blocks long.

Confirm that partition was extended:

rytis@aws:~$ df -h
Filesystem      Size  Used Avail Use% Mounted on
udev            3.8G     0  3.8G   0% /dev
tmpfs           764M   81M  683M  11% /run
/dev/nvme0n1p1   39G   26G   14G  66% /
tmpfs           3.8G  8.0K  3.8G   1% /dev/shm
tmpfs           5.0M     0  5.0M   0% /run/lock
tmpfs           3.8G     0  3.8G   0% /sys/fs/cgroup
tmpfs           764M     0  764M   0% /run/user/1002

B. If filesystem type is XFS:

  1. If xfsprogs is not installed, install it:
sudo apt install xfsprogs
  1. Extend partition:
sudo xfs_growfs -d /
  1. Confirm changes:
rytis@aws:~$ df -h
Filesystem      Size  Used Avail Use% Mounted on
udev            3.8G     0  3.8G   0% /dev
tmpfs           764M   81M  683M  11% /run
/dev/nvme0n1p1   39G   26G   14G  66% /
tmpfs           3.8G  8.0K  3.8G   1% /dev/shm
tmpfs           5.0M     0  5.0M   0% /run/lock
tmpfs           3.8G     0  3.8G   0% /sys/fs/cgroup
tmpfs           764M     0  764M   0% /run/user/1002

TL;DR;

sudo su
lsblk
growpart /dev/nvme0n1 1
df -Th
resize2fs /dev/nvme0n1p1
df -h

Even shorter:

sudo su
growpart /dev/nvme0n1 1 && resize2fs /dev/nvme0n1p1 && df -h