Using BRMS Archiving, Retrieval and "Re-Free" functions

Archiving, in its original form, is a technique for saving valuable disk space by selecting infrequently used objects, saving them to tape, and then deleting them from disk. In previous releases, the concept of archiving using save with storage freed was introduced. The storage for the object is freed as part of the save operation. Archiving of data to tape or to a save file on secondary disk saves disk space on primary (fast) disk because it moves the object to a less expensive form of storage. BRMS tracks the information about the objects that you archive. When you recall the object by using dynamic retrieval, you restore the save file to the place from which it was saved. Full tape automation allows you to perform archiving quickly and effortlessly while appearing seamless in its operation.

The archival function allows you to archive objects to tape. However, only the following object types can be archived and dynamically retrieved:

Database files, including QHST file (member level):

o	Source files (member level)
o	Document library objects
o	Stream files

Notes:

1.	It is recommended that you not archive IBM files or objects.
2.	If an object has been saved with storage freed by any means other than BRMS, an inventory of the archived object is not performed by BRMS. In this case, BRMS cannot locate and restore the object without manual intervention. You will likely receive a message that the object cannot be found.
3.	To use BRMS archiving and dynamic retrieval, the following is required: 57xxBR1 Option 2 , FC5102 - BRMS - Advanced Functions Feature.
4.	Objects without members are not candidates to be archived because they cannot be saved STG(*FREE).

 

1. You must first set up an Archive Control Group
   1. Using the information below, you can determine what criteria you want to use to archive objects.
2. Then you must run or schedule this control group to run on a periodic basis.

The following is taken from TechNote: N1011200
How BRMS Determines What Objects to Archive
There are numerous parameters in the BRMS Archive parameter and BRMS Archive control group attributes that determine if an object or file is subject to be archived:

• ASP low storage threshold:

Specifies the percent storage utilization that, if exceeded, will allow objects that meet all other archive criteria to be archived. When the storage utilization of an ASP is less than this percent, objects in this ASP are not archived.

• Date type for archival:

Specifies whether the last change date, last use date, or both are used to determine the number of days of inactivity. The types of objects that support this option are *FILE, DLO, and stream files.

• Inactivity limit:

Specifies the number of days of inactivity before an object is archived.

• Object size greater than:

Specifies the size in megabytes that an object must exceed before it can be a candidate for archival. Only objects that meet this size specification and all other archive criteria will be saved.

• Objects able to be freed:

Specifies whether or not objects that have storage related to the object description are included in the archive process. Object types that have storage related to their object descriptions are *FILE, *PGM, *JRNRCV, *SQLPKG, DLO and byte stream file objects.

• Retain object description:

Specifies whether the object description for an object is left online when the object is archived.

• Objects not able to be freed:

Specifies whether or not objects that do not have storage related to the object description are included in the archive process. Object types that have storage related to their object descriptions are *FILE, *PGM, *JRNRCV, *SQLPKG, DLO and byte stream file objects.

• Days used (per month) less than:

Specifies whether objects are to be included in the archive operation based on the object's frequency of use. The frequency of use of an object is based on the average number of days it has been used in a month.

Additional Information
BRMS first looks at Days used (per month) less than parameter. If that is 0, it is ignored. If it is a number, 1-31, BRMS checks if it has been used less than that number of times in the last 30 days. BRMS uses this algorithm to calculate: (30 * daysUsedCount) / (today - dateReset or if blank, the createdate) .

When looking at an objects attributes, the values in the algorithm are as follows:

Creation information:
Creation date/time . . . . . . . . . : 08/19/11 12:31:13
Created by user . . . . . . . . . . : ANYUSER
System created on . . . . . . . . . : SYSTEMA
Object domain . . . . . . . . . . . : *SYSTEM
Change/Usage information:
Change date/time . . . . . . . . . . : 08/19/11 12:31:13
Usage data collected . . . . . . . . : YES
Last used date . . . . . . . . . . . : 01/17/12
Days used count . . . . . . . . . . : 2
Reset date . . . . . . . . . . . . :

If the object passes this test, the inactivity value is used. If the object does not pass this test, it is not a candidate to be archived.

 

What does it mean to "Re-Free" an object with BRMS. Essentially, an object is "Re-Freed" by automatically saving it to a SAVF with STORAGE = *FREE, using BRMS. Then that SAVF is deleted automatically by BRMS.

Objects are available to be "Re-Free" when all of the following criteria are met:

• It has not changed since it was originally retrieved.
• It has reached the number of days specified in the RETRIEVED OBJECT RETENTION parameter in the ARCHIVE POLICY.
• You have run STRMNTBRM AUTO-RETRIEVED OBJECTS: REFREE = *YES

NOTE:

If the object has changed or the RETRIEVED OBJECT RETENTION is set to *NOMAX and the STRMNTBRM is run with REFREE = *YES, nothing occurs. The object must be re-archived using the archive process noted above.