2015-01-29-attach-volume.md

layout	title	categories	lang	author
post	Attach additional storage to an instance	instances	en	NicolasLM

Thanks to OpenStack Cinder you can attach additional disk space to your instance. This guide will show you how to use this feature.

Create a volume

On Cinder a drive is called a volume. The first thing you need to do is to create a new volume in the region you want. To do that go to OpenStack Horizon in the volumes area.

Click on Create Volume and a form asking a few parameters will appear. Select the type of volume you need, its name, size, nova as availability zone and select empty volume. Finally you can create the volume.

Attach the volume to an instance

From the volumes list click on More and Edit Attachments to attach a volume to a running instance.

Select the instance on which you want extra disk space and click on Attach Volume.

You will see to which device your volume is attached to. This device will be accessible directly into your instance.

Format and mount the volume

Once the volume is attached to your instance you need to format the device and mount it. This operations are different if you use GNU/Linux or Windows instances.

GNU/Linux

From a shell issue the lsblk command, this will list the block devices you can use:

admin@mariadb:~$ lsblk
NAME   MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT
vda    253:0    0   160G  0 disk
└─vda1 253:1    0   160G  0 part /
vdb    253:16   0   9.8T  0 disk

The device /dev/vda is the root disk of your system. It has one partition called /dev/vda1 filling all the space. Then you can see /dev/vdb which is the volume you just attached.

In order to be able to use it you need to format it and mount it somewhere.
This is easily done with:

admin@mariadb:~$ sudo mkfs.ext4 /dev/vdb
Allocating group tables: done
Writing inode tables: done
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: done

admin@mariadb:~$ sudo mkdir /mnt/database

admin@mariadb:~$ sudo mount /dev/vdb /mnt/database/

admin@mariadb:~$ df -h
Filesystem      Size  Used Avail Use% Mounted on
/dev/vda1       158G  1.1G  150G   1% /
/dev/vdb        9.7T   38M  9.3T   1% /mnt/database

You can now store your files on the directory /mnt/database.

Microsoft Windows Server

Right click on the Windows button and select Disk management.

There you can right click on Disk 1 and select Online, then again select New Simple Volume. Select the options you want, the default selected one are fine.

Once the formatting is done, a new drive will be available on your instance.