Innovation Data Processing | FDRARC – Data Migration & Space Management for z/OS

FDRARC Introduction

FDRARC is a high-performance data archival tool that can be used to control the consumption of your z/OS disk storage.

With FDRARC, unwanted and expired data sets can be quickly and efficiently migrated to a less expensive medium, such as a high-capacity tape, a VTS, or to a compressed format on another disk.

Migrated data sets are recorded in a control file and recataloged to a volser of MIGRAT. FDRARC's auto-recall facility ensures that a migrated data set can be easily and transparently recalled to disk if it is referenced by a batch job, online application, or an end-user.

Key Features & Benefits

FDRARC is incredibly easy to use and set up.
It can be installed and operational in less than an hour.
When operating in a DFSMS environment, it can utilize the “space management” criteria set in the DFSMS Management Class for each data set on each volume processed.
FDRARC can be used on a single volume, a pool of volumes, or your entire DASD subsystem.
Thresholds can be established on volumes so that FDRARC space management can be invoked to maintain a certain level of free space within the DASD storage pool.
FDRARC can also be used in non-DFSMS environments, such as development or testing systems, where user data often goes unused for long periods of time.

Simulation with FDRQUERY

FDRARC includes a report utility called FDRQUERY, which can be used to illustrate the effects of a data migration policy against one or more disk volumes using a range of “not-referenced” criteria.

In the example below, we are looking at all volumes belonging to the DFSMS Storage Group called ‘DEV’. The details for one volume (DEV002) are shown, together with the Summary report for all 6 volumes in the Storage Group.

                           SUMMARY LEVEL BY VOLUME SERIAL NUMBER

                   ALLOC     BEFORE    AFTER     LAST   USED           SAVINGS IF MIGRATED
VOLSER DEVTYPE     TRACKS    %ALLOC   %ALLOC     DAYS   DATE         DSMS   TRACKS    %SAVED
------ -------     ------    ------   ------     ----   ----         ----   ------    ------
DEV002 3390-3       43665    80.18%   20.00%      30 2005220          786    33643    77.04%
                                      27.67%      60 2005190          712    29802    68.25%
                                      31.33%      90 2005160          685    27971    64.05%
                                      27.67%     120 2005130          643    25635    58.70%

                               SUMMARY LEVEL BY DEVICE TYPE
                   ALLOC     BEFORE    AFTER     LAST   USED           SAVINGS IF MIGRATED
VOLCNT DEVTYPE     TRACKS    %ALLOC   %ALLOC     DAYS   DATE         DSMS   TRACKS    %SAVED
------ -------     ------    ------   ------     ----   ----         ----   ------    ------
6       3390-3     224911    74.84%   34.92%      30 2005220         1148   119971    53.34%
                                      36.32%      60 2005190         1070   115762    51.47%
                                      37.12%      90 2005160         1037   113340    50.39%
                                      37.92%     120 2005130          994   110944    49.32%

The report shows that DEV002 is currently 80% allocated. If FDRARC was run against the volume to remove all data sets not referenced in the previous 30 days, the allocation would come down to 20%. 786 data sets would be removed from the volume (33,643 tracks), saving 77% of the allocated space.

If a less severe criterion were used for the migration, the savings would not be as high. The report shows the results of using ‘not-referenced-in’ criteria of 30, 60, 90 and 120 days.

The Summary report shows that, across all six 3390-3 volumes in the DEV Storage Group, the current allocation level is 74%. With 30-day migration criterion, this would be reduced to 34%, with over 1,100 data sets (nearly 120,000) tracks being reclaimed.

Tidying up Freespace with FASTCPK

By removing unwanted data sets from disk, FDRARC will naturally create areas of free space on a volume, and for best performance, these freespace areas should ideally be consolidated.

See the FASTCPK section for a quick and easy solution for consolidating free space on a volume into as few as one or two contiguous areas.

Summary

Although the price per megabyte of z/OS disk storage has dropped considerably over the past few years, the demand has increased in most installations. For this reason, disk storage remains a significant part of the Data Center budget.

The available DASD space at an installation, however cheap, needs to be used as efficiently as possible. Unfortunately, DASD volumes often contain datasets that no longer need to be on disk.

In many cases, datasets are created by a batch job or TSO user and never used again. Other datasets are used only on an infrequent basis—perhaps just once a year—and do not need to be on disk in the interim period. In addition, there are also the datasets that do not meet installation standards (e.g. uncataloged/expired) which need to be regularly dealt with.

FDRARC provides an excellent way to control the consumption of DASD resources by ensuring that expired or unwanted datasets are either deleted or moved to a less expensive medium (e.g. tape or compressed DASD).

For more introductory information on FDRARC, see the Product Portfolio Sheet

For more technical detail on FDRARC, see the Tech Detail section.

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