Attaching and Accessing Volumes to an instance

You can only attach a volume to one instance at a time.

Attaching Volume

Web Interface

1.	Click the drop-down menu on the right-hand side (in `Actions` column) and select `MANAGE ATTACHMENTS`
2.	Select the right instance and press `ATTACH VOLUME`
3.	Note the path in the `Attached To` column of the volume

Command-Line

Get the Server ID (Instances) and Volume ID (Volume) using command

$ openstack server list
+--------------------------------------+--------------------------+--------+----------------------------------------+---------------------------------------------------------+--------------+
| ID                                   | Name                     | Status | Networks                               | Image                                                   | Flavor       |
+--------------------------------------+--------------------------+--------+----------------------------------------+---------------------------------------------------------+--------------+
| 6b2bedc4-9d8e-4bf3-be63-1dd49bc2e188 | test-resize-rebuild      | ACTIVE | Internal=172.16.102.207                | ubuntu-focal-20.04-gui                                  | c3.small     |
+--------------------------------------+--------------------------+--------+----------------------------------------+---------------------------------------------------------+--------------+
$ openstack volume list
+--------------------------------------+-------------------+-----------+------+-----------------------------------+
| ID                                   | Name              | Status    | Size | Attached to                       |
+--------------------------------------+-------------------+-----------+------+-----------------------------------+
| 2d61791d-5f52-46e1-81ac-05221c308fe8 | test-cli-snapshot | available |    3 |                                   |
+--------------------------------------+-------------------+-----------+------+-----------------------------------+

Run

openstack server add volume <server-id> <volume-id> --device <device-name>

$ openstack server add volume 6b2bedc4-9d8e-4bf3-be63-1dd49bc2e188 2d61791d-5f52-46e1-81ac-05221c308fe8 --device /dev/vdb
+-----------+--------------------------------------+
| Field     | Value                                |
+-----------+--------------------------------------+
| ID        | 2d61791d-5f52-46e1-81ac-05221c308fe8 |
| Server ID | 6b2bedc4-9d8e-4bf3-be63-1dd49bc2e188 |
| Volume ID | 2d61791d-5f52-46e1-81ac-05221c308fe8 |
| Device    | /dev/vdb                             |
+-----------+--------------------------------------+

Accessing the volume

Log-in to the attached instance using SSH
(Optional only for new volume) Format the volume (we use ext4 here and assume the attach point is /dev/vdb) (Formatting will wipe your data):
```
sudo mkfs.ext4 /dev/vdb
```

Use lsblk to confirm the device path (usually type disk). The value shown in OpenStack can be inaccurate.

$ lsblk

NAME    MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
loop0     7:0    0 73.1M  1 loop /snap/lxd/21902
loop1     7:1    0 55.4M  1 loop /snap/core18/2128
loop3     7:3    0 72.6M  1 loop /snap/lxd/21750
loop4     7:4    0 61.9M  1 loop /snap/core20/1169
loop5     7:5    0 32.5M  1 loop /snap/snapd/13640
loop7     7:7    0 42.2M  1 loop /snap/snapd/14066
loop8     7:8    0 55.5M  1 loop /snap/core18/2253
loop9     7:9    0 61.9M  1 loop /snap/core20/1242
sr0      11:0    1  470K  0 rom  /mnt/context
vda     252:0    0   20G  0 disk
├─vda1  252:1    0 19.9G  0 part /
├─vda14 252:14   0    4M  0 part
└─vda15 252:15   0  106M  0 part /boot/efi
vdc     252:32   0    3G  0 disk

Mount the volume (we use the folder /mnt/test-volume as example)
```
sudo mkdir /mnt/test-volume
```
Add this mount point to /etc/fstab, so it will be mounted automatically on startup
```
sudo vim /etc/fstab 
```

Add/edit the following line:

/dev/vdb /mnt/test-volume ext4 defaults 0 0

You still need to manually mount it now
```
sudo mount /mnt/test-volume
```
(Optional)You may also want to change the permission of the directory using chmod to enable read/write without sudo
```
 chmod
```