Attach an additional disk

To attach an additional disk to an instance, you first need to create and attach a volume. Once this is done, perform the following steps:

1. List all block devices and find the new disk. In this case, the device name is vdb.

   user@testVM:~$ lsblk
   NAME    MAJ:MIN RM  SIZE RO TYPE MOUNTPOINTS
   vda     252:0    0   64G  0 disk
   ├─vda1  252:1    0 63.9G  0 part /
   ├─vda14 252:14   0    4M  0 part
   └─vda15 252:15   0  106M  0 part /boot/efi
   vdb     252:32   0  100G  0 disk

2. Create the partition on the additional disk using the commands below (/dev/vdb):

   user@testVM:~$ sudo fdisk /dev/vdb.     #start fdisk on the partition
   Command (m for help): n.                #create a new partition
   Partition type
     p   primary (0 primary, 0 extended, 4 free)
     e   extended (container for logical partitions)
   Select (default p): p                   #select primary
   Partition number (1-4, default 1):
   First sector (2048-209715199, default 2048):
   Last sector, +/-sectors or +/-size{K,M,G,T,P} (2048-209715199, default 209715199):
   
   Created a new partition 1 of type 'Linux' and of size 100 GiB.
   
   Command (m for help): w                 #write changes to partition table
   The partition table has been altered.
   Calling ioctl() to re-read partition table.
   Syncing disks.

   Verify that the new partition has been created:

   user@testVM:~$ lsblk
   NAME    MAJ:MIN RM  SIZE RO TYPE MOUNTPOINTS
   vda     252:0    0   64G  0 disk
   ├─vda1  252:1    0 63.9G  0 part /
   ├─vda14 252:14   0    4M  0 part
   └─vda15 252:15   0  106M  0 part /boot/efi
   vdb     252:32   0  100G  0 disk
   └─vdb1  252:33   0  100G  0 part

3. Format the new partition, e.g. using the ext4 file system.

   sudo mkfs.ext4 /dev/vdb1

4. Create a folder and mount the partition.

   sudo mkdir /mnt/mymountpoint
   sudo mount /dev/sdb1/ /mnt/mymountpoint

The mount is not persistent and the disk will be detached during an instance reboot. In order to persistent the mount, it needs to be added to the /etc/fstab file.

How to make the mount persistent:

Always use mounts via UUID. Device names won’t always remain the same after e.g. a shelve/unshelve or image change.

1. Retrieve the UUID of the new volume.

   user@testVM:~$ sudo blkid
   /dev/vda1: LABEL="cloudimg-rootfs" UUID="1a1bd84e-9ac2-4024-8eea-33d95eb361ec" BLOCK_SIZE="4096" TYPE="ext4" PARTUUID="bb97197b-5a20-4022-998f-422bd8f318ce"
   /dev/vdb1: UUID="c82f02d5-d79f-43d9-840c-42a02bacb539" BLOCK_SIZE="4096" TYPE="ext4" PARTUUID="b78958f9-01"

2. Add the mountpoint to /etc/fstab.
   bash UUID=c82f02d5-d79f-43d9-840c-42a02bacb539 /mnt/mymountpoint ext4 defaults 0 0