Resizing EBS without Downtime

In order to extend the volume size, follow these simple steps:

1. Login to your AWS console
2. Choose “EC2” from the services list
3. Click on “Volumes” under ELASTIC BLOCK STORE menu (on the left)
4. Choose the volume that you want to resize, right-click on “Modify Volume”

5. Set the new size for your EBS volume (in this case i extended an 8GB volume to 20GB)

6. Click on modify.

7. Finish in the machine’s shell

Type the following command to list our block devices:

[ec2-user ~]$ lsblk

You should be able to see something like this:

NAME    MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
xvda    202:0    0  20G  0 disk 
└─xvda1 202:1    0  8G   0 part /

The root volume reflects the new size, 20GB, the size of the partition reflects the original size, 8 GB, and must be extended before you can extend the file system.

To do so, type the following command:

[ec2-user ~]$ sudo growpart /dev/xvda 1

Watch out for and double! Triple! check the partition name

Now we can check that the partition reflects the increased volume size

NAME    MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
xvda    202:0    0  20G  0 disk 
└─xvda1 202:1    0  20G  0 part /

Now, we need to extend the filesystem itself.
If the filesystem is an ext2, ext3, or ext4, type:

[ec2-user ~]$ sudo resize2fs /dev/xvda1

If XFS, then type:

[ec2-user ~]$ sudo xfs_growfs /dev/xvda1

Finally check the extended filesystem by typing:

[ec2-user ~]$ df -h

If everything went right, we should be able to see our effective filesystem extended size:

Filesystem      Size  Used Avail Use% Mounted on
devtmpfs        980M     0  980M   0% /dev
tmpfs           997M     0  997M   0% /dev/shm
tmpfs           997M  440K  997M   1% /run
tmpfs           997M     0  997M   0% /sys/fs/cgroup
/dev/xvda1      20G   1,4G   19G   7% /

You have just extended your EBS volume size with 0 downtime, enjoy!