CNS Offsite details


Herein are discussed, in some detail, the states through which tapes are moved during offsite processing. Additionally, the processing phases are discussed. The descriptions of these states and phases are interleaved, in an arrangement which (it is assiduously hoped) will improve the clarity of the discussion.

Tape states

NEW. Tapes delivered from the manufacturer. These are traditionally devoid of label, either physical or electronic. The physical label is applied by CNS operations, and the electronic label is applied by TSM on first introduction of the tape, in FIXME: phase 0a of tape processing.

Phase 0a. Physical label is applied to a tape, and the tape is inserted into the library. LABEL LIBVOLUME is run, and the tape is checked into the logical library on the library manager instance.

SCRATCH. SCRATCH Tapes have been inserted into the physical library, checked into the logical library of the library manager instance. These tapes are available to be requested by a process or session. The library manager instance doles these tapes out to client instances as needed. All scratch tapes for the entirety of the TSM infrastructure are maintained in this unified scratch pool.

Phase 1. The tape is required for storage. A TSM server makes a request, and the tape is mounted and written to. No operator or administrator intervention is required.

MOUNTABLE. MOUNTABLE tapes have been written to, and which are still present in the physical library. Many tapes in MOUNTABLE state are primary or local-copy. Only some of them, those in designated copy pools, are candidates for offsite treatment. These candidates will be ejected from the library according to schedules maintained in the various instances.

Phase 2. A copy-pool tape has been written to, and has been deemed ready for storage. MOVE DRMEDIA occurs automatically, and the tape is ejected from the library. Notification goes out to operations staff, who take the tape from the library I/O station, and store it in the outgoing rack.

NOTMOUNTABLE. NOTMOUNTABLE tapes have been written to, and which have been ejected from the physical library. They are presumed still to be onsite. At CNS, these tapes should be present either in the I/O drawer of the library, or in the 'OSG OUTGOING' rack.

Phase 3. At the next courier visit, the tape is handed over and transported. We do not separately record the transition from courier custody to vault placement, so we deem the tapes 'in the vault' as soon as they are handed over to the courier. The transition to VAULT is directed manually by operations staff for each volume.

VAULT. Tapes which have been handed over to the courier for storage. These tapes require an interaction with the storage service to reclaim. They may be still en route, or they may have arrived at the storage facility.

Phase 4. Eventually a tape is deemed empty. In the case of copy storage pool volumes, this happens when the volume has been reclaimed and the reuse delay has completed. In the case of database backup volumes, this happens when the database backup has been deleted from the volume history. At that point the TSM server in question changes its status to VAULTRETRIEVE. No operator or administrator intervention is required.

VAULTRETRIEVE. Tapes which are resident at the storage facility, and have been deemed ready for retrieval. At the next interaction, these tapes should be requested from the courier service. These tapes are administratively 'blank'.

Phase 5. When the courier returns the tape, operations staff notes this by means of MOVE DRMEDIA to onsiteretrieve for each volume returned.

ONSITERETRIEVE. Tapes which have been retrieved from the courier service. They are 'blank' and are ready to place on the shelf.

Phase 6. Tapes which achieve ONSITERETRIEVE state are automatically removed from both the volume records and the library scratch pools. These tapes are placed on the 'EMPTY' shelf, ready to be checked in again at next need.

SHELF. Tapes with physical and electronic labels, present on a shelf in the machine room. These may have been kicked out of the library for space reasons, or they might have

Phase 0b. Tapes on the shelf are inserted into the physical library and checked in to the logical library as the level of scratch tapes falls below predetermined levels [which are documented elsewhere].

Phase 0c. If space in the library is at a premium, tapes in the SCRATCH state can simply be checked out of the library, and placed on the shelf.