Recurring Volume Attachments tab
Information in the Recurring Volume Attachments tab specify which Snapshots (or Volumes) should be attached to a Server the next time that it is launched. All of the Servers to which a Volume is scheduled to be attached at boot displayed in the "Recurring Attachments" tab of the Volume itself.
Clouds > Cloud > Volume Snapshots > Show > Recurring Attachments tab
Runnable - The Server or Server Array to which a Volume attachment is scheduled.
Runnable Type - Either Server or Server Array, depending on how "Runnable" is scheduled.
Device - If a Volume is attached to an instance, the system identifier of the block device as it is manifested on the running Server is displayed (if known and reported by the cloud). If the Device of the Volume is not known it is labeled as such along with a unique/random number. Example: unknown_1438:1235.
Size - Size of a Volume (or snapshot) in gigabytes (GB).
Actions - Lists the legal actions you can execute against the snapshot. For example, delete.