| Root disk | /dev/vda, automatically mounted on / | Operating system and applications | - High IOPS and throughput (Solid State Disks in RAID 0)
- Included in instance snapshots
| - Limited size
- No redundancy
- Deleted when virtual machine is deleted
- Not automatically backed up
|
| Attached volumes aka Block Storage aka Cinder (Backed by Ceph) | /dev/vdb and subsequent, not automatically mounted | Persistent storage of large volumes of data | - Large size
- High throughput
- Built-in redundancy
- Exists until deleted by owner
- Can be detached from one VM, then re-attached to another.
- Can create point-in-time volume snapshots
| - Lower IOPS
- Not automatically backed up
|
| NCI Global Data Filesystems | NFS exported (see Appendix C for more information) | Use of data sets across different NCI computing platforms, shared access to data from multiple projects, storage of very large data sets | - Common data storage available to all NCI computing platforms
- Persistent for the life of the project
- Shared access via NFS across multiple instances
- Shared access across multiple projects
- Very large storage capacity
- Easy access to additional data management facilities
| - Access via NFS imposes limitations in performance
- Access via NFS requires additional set up and adds complexity
|