Live volume extension

Note: before you start this tutorial, please create a backup of your volume. You can find a tutorial for that here.

Often, you can find yourself unsure what amount of storage an instance will need. You may start it at a certain size before realizing you need more space once it’s running. While adding more space to a volume is straightforward, doing so while keeping it in use can pose problems. This tutorial will teach you how to extend the size of a secondary volume, without having to unmount it first. This allows you to add more space to your instance while keeping it running.

Building and adding a secondary volume with LVM

Start by creating an instance using a standard Ubuntu image, then create an additional volume and attach it to your instance. You can find the tutorials for this in the Getting Started section

Now, create an LVM Volume Group on the new volume:

vgcreate /dev/MyVG01 /dev/vdb

Once you've done that, create a Logical Volume in the new Volume Group:

lvcreate -L +9G --name test MyVG01

You have now built and added a secondary volume with an LVM Volume Group

Build and extend a partition containing a new Volume live using LVM

First, create an ext4 partition in the new Logical Volume:

mkfs -t ext4 /dev/MyVG01/test

Now mount the new partition:

mkdir /mnt/tes mount -rw /dev/MyVG01/test /mnt/test

Create another new volume and attach it to the instance. Now, you can extend the Volume Group:

vgextend /dev/MyVG01 /dev/vdc

Followed by extending the Logical Volume:

-L +11G /dev/MyVG01/test

And finally, resize the partition to the new maximum size:

resize2fs /dev/MyVG01/test

You have now used LVM to build and extend a partition containing a new volume while live