OSMC Storage Management Cycle Flow

OSMC Storage Management Cycle Flow

- OSMC is started for a Storage Group (by command or via Cycle Start Time and Cycle End Time parms in the Storage Group definition)

- The Storage Group's DB2 Object Directory Table is searched to select all objects with a Pending Action Date of today or prior (ODPENDDT).

- For each selected object (Expire? Backup? Transition?):
If there is a real date in the Expiration Date field (ODEXPDT) and it has expired: call user exit CBRHADUX to attempt to delete the object. If CBRHADUX says it is OK to delete, schedule the delete and if it is on optical or tape, set indicator to show that VOLUME expiration needs to be checked later. No further processing (backup, transition, etc.) is required for the deleted object.
Else ODEXPDT is 0001-01-01 (so use criteria from Management Class definition):
The object's current definitions for Management Class and Storage Class are retrieved from SMS. Check expiration criteria from the Management Class definition. If it is time to expire, call CBRHADUX etc (like above).

- Need a Backup?: If not expiring, check Management Class definition for AUTO BACKUP. If "Y" and it doesn't have a backup already (ODBKLOC is blank), then schedule a backup. Backup Storage group is specified in the CBROAMxx PARMLIB member (global or per Storage Group)

- Time to Transition?: If the current Management Class has transition criteria, the SMS ACS routines are called in environment CTRANS (first Storage Class, then Management Class) Potentially, a new Storage Class and Management Class are now assigned so we check and process Expiration and Backup just like before.

- New platform? Where are we now? (DASD, OPTICAL, or TAPE) Check
ODLOCFL: "D" for DASD, "T" for TAPE, or blank for Optical. Check for new platform determined by Storage Class.
If Storage Class INITIAL ACCESS RESPONSE=0 its DASD,
Else if Storage Class SUSTAINED DATA RATE >= 3 it is Tape, Else its Optical
Schedule the move to LCS (OAM's Library Control System).
For example, to move from DASD to Optical: Schedule a read from DASD, then write to Optical, then delete from DASD.

- OSMC sends the objects into a pipeline of modules (Read DASD, READ Optical or Tape, Write DASD, Write Optical, Write Tape, Write Backup, Volume Expiration Check, Update directory) OSMC's Router makes sure that every thing that has been scheduled is done.

- Calculate the new Pending Action Date (ODPENDDT) using the earliest criteria from the new Management Class (Expiration or Transition).

- Call DB2 to update the object's row in the Object Directory Table

- After all individual Objects are processed:
Shelf Manager: Check for expired Tape and Optical Volumes
DASD Space Manager: Only if a previous attempt to write to DASD failed