Introduction
Files archived by MediaHaven / DigiHaven are written to storage using a particular number of copies.
For example
1 copy: This case is not advised as it goes against our archival mandate
2 copies: The most common case where we write a main and backup copy on disk
3 copies: The case at Meemoo where we write to A, B and C tapes
Concepts
The storage concepts in the engine have a tree structure with progressive information, each concept is a child concept of the previous.
Super clusters : groups pools which are mirrored across all organisations (future concept)
Cluster groups: groups pools across all organisations having the same role (one of the mirrored copies)
Clusters: pool from a cluster group for a specific organisation
Storage Pools: pool corresponding with a protocol
Example
Super cluster for all LTO-8 tapes named “tape_8” with contains all A, B and C tapes
Cluster group for all LTO-8 archive tapes named “tape_archive_8”
Cluster for the archive LTO-8 tapes of the organisation vrt named “vrt_tape_archive_8”
Storage Pool for the tape
A00154L8
belonging to the cluster “vrt_tape_archive_8”
Tree
In this diagram, the 3rd copy, namely VAULT/C tapes are omitted.
Properties
Concept | Property | Examples | Description |
---|---|---|---|
Cluster group | cluster group ID | Unique label for the cluster group | |
Cluster group | type | MOB, BROWSE, CACHE |
|
Cluster group | role |
| |
Cluster group | tape_like |
| Pattern to which the tape barcodes correspond |
Cluster group | Free space: calculate |
| |
Cluster group | Free space: storage path |
| Server specified by the URI to contact to determine the free space parameters of the volume mounted on the path specified by the URI |
Cluster group | Free space: add queued space | Whether to add the queued space to the free space, must be enabled when the ingest and archive storage share the same physical volume | |
Cluster | cluster ID |
| Unique label for the cluster |
Cluster | organisation ID |
|
|
Storage Pool | storage pool ID |
| Unique ID (integer) for the storage pool |
Storage Pool | ID in cluster | 1 | When allocating storage it selects mirrored copies across pools of multiple cluster groups having the same ID in cluster |
Storage Pool | Total Space | Total storage in bytes | |
Storage Pool | Free Space | Remaining storage in bytes | |
Storage Pool | Keep Free Space |
| |
Storage Pool | Queued space | Free space likely to be consumed in the future, i.e. when scheduling jobs to write to tape | |
Storage Pool | Is Online |
| When false this pool is currently unavailable, for example when a tape is removed from the tape library |
Storage Pool | Protocol, Credentials, Server, Port, Path | ftp://user:***@server:port/path | Forms together an URI |
Storage Pool | Class |
| Object storage can write files in different modes |