Science in the Cloud 2019

Storage Volumes

Volumes are small virtual filesystems that may be attached to running/actice Instances. Files/data saved to a Volume are maintained across successive attachment/detachment actions and can be moved between Instances.

Creating a Volume

A Volume must be created before it can be attached to an active Instance.

From the Jetstream Atmosphere Dashboard:

• Click on Projects
• Select your Project
• Click New>Volume
  
• A window will pop up in which you can:
  
• Name the Volume relative to the contents
• Enter the desired volume size
  (subject to your allocation limits)
• Select the Provider on which the Volume will reside.
  Note: Volumes can only be attached to Instances on the same provider.

After creation, the volume will appear in your list of available volumes:

Attaching a Volume

After creation a volume can be attached to an Instance on the same provider.

• Click on the Volume name
• On the next page under Actions, click Attach
  
• You can select any ACTIVE Instance in the same provider
  
• The Volume will be automatically mounted on the selected Instance with a device and directory name corresponding alphabetically to the order of attachment.
• e.g. the first volume attached will be the second device (/dev/sdb) after the Instance root directory (/dev/sda), and will be mounted as in directory /vol_b.

[USER@js-169-6 ~]$ df -kh
Filesystem      Size  Used Avail Use% Mounted on
/dev/sda1        59G  3.0G   54G   6% /
tmpfs           7.8G  148K  7.8G   1% /dev/shm
/dev/sdb        9.9G  151M  9.2G   2% /vol_b

### Detaching a Volume

Volumes can only be detached from ACTIVE Instances but any files/data currently stored on the Volume will be maintained.

To detach a Volume:

• Select a desired Dashboard> Project> Volume
• Click in the Actions menu
• Volumes will fail to detach if they are in-use.
  • From the command-line you can try
    fuser -km /<volume>
    to kill any processes using a volume