1st August 2006
Recent changes to FLEX Inquiry (FLEX), have greatly enhanced its usefulness as a way of safeguarding files without the use of the full FLEX program FamilyManager.
The Archive System
The first relevant features revolve around the Unisys Archive system (Archiving in this article is not to be confused with the ancient disused Archiving MCP option). This system was implemented in the early 90s originally as a replacement to Cataloguing, but it quickly became apparent that the lack of some critical features of Cataloguing, particularly the integration with a Volume database, i.e. the Volume Library, meant that it was impractical except for low-volume use. Metalogic has been working intermittently with Unisys to plug some of the deficiencies in Archiving and has succeeded in getting some critical modifications.
Archiving has the big advantage that it does not change the system-wide handling of the directory, it is very much an add-on and any performance impact it has is limited to the families it is used for. This allows it to be introduced step-by-step.
In many ways Archiving is similar to Cataloguing, and was modelled on it. That means that we have been able to modify FLEX so that the familiar interfaces work with both. For example, to see the Archiving information for file A/B in FLEX, just do FILES A/B:CAT, exactly like in Cataloguing. Similarly, the information is contained in a file for each family with a similar structure to a Catalog, so FLEX’s :LINEAR option can now be used too.
Note that use of the LINEAR (also LIN) option to search an Archive does not return info about files that are resident, but only those that have been subjected to ARCHIVE Backup. Also, if an Archive is named explicitly with Flex’s MAINT ALT CAT, the FAMILYNAME attribute will be unavailable in the Archive entry. When it is implicit, FLEX can take the FAMILYNAME from the Archive TITLE attribute.
LOAD vs. Archiving
When Cataloguing is reset, a FLEX LOAD will search the Archive and issue a COPY from the relevant Backup media. The tape mount optimization is done as usual, so it is nearly always more efficient to LOAD with FLEX than to use a simple ARCHIVE RESTORE. However, FLEX currently only considers the first 2 backups for the LOAD, as in Cataloguing, even though a file can have up to 4 backups in an Archive block. This limitation will be raised in the future.
Re-loading a file that has been accidentally ZAPped (subject to a REMOVE and ARCHIVE PURGE) is done in the same way. Point the MAINT ALT CAT at a backup copy of the relevant Archive and use the LOAD:LIN command in FLEX Inquiry.
Re-loading all the files on a Family that has been lost is somewhat different because the Archive does not have info about what files were resident when the pack crashed. The alternate procedure, using ODT commands and FLEX functions, is as follows:
- COPYCAT the SYSTEM/ACCESS file
- RC in a new pack with the correct FamilyName/SerialNo
- Do a MAINT ALT CAT to the copied ACCESS
- LOAD (*)= ON <family>:FAST
The old SYSTEM/ACCESS still contains the info on what files were resident and a LOAD:FAST will re-load via the Archive (FLEX’s :FAST modifier reads the SYSTEM/ACCESS file directly and is very, very fast for file name searches).
BACKUP Command
FLEX has always had the ability to make backups, but the method involved manual scripting of WFL job generation and then STARTing them. The BACKUP command greatly simplifies this; BACKUP can be used like any other command and both the :FLAT, and :ACT options enhance its use. The command will generate a COPY to TAPE, but the default tape name, and even destination can be over-ridden using a TO modifier.
If the :CAT option is used, the COPY becomes either a COPY&BACKUP on Cataloguing, or an ARCHIVE FULL on Archiving. The :TWO option will make 2 copies in the same LIBRARY/MAINTENANCE run.
Detailed descriptions of these changes are not yet available in FLEX documentation but more information can be found by browsing the DNote changes for FLEX and FLEX/LIBRARY using the following links:
