# Determining Index & Data Block Usage for the ROSLIBS - ROSTAT

Document ID : KB000028104
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Introduction:

ROSTAT will analyze the Roscoe library system and format a report on the library space statistics. This should be done nightly as part of the Roscoe backup process.

```//ROSTAT   EXEC PGM=ROSTAT,PARM=roscoejobname
//STEPLIB  DD  DSN=CAI.RO60LIB,DISP=SHR
//ROSLIB00 DD  DSN=CAI.ROSLIB00,DISP=OLD
//ROSLIB01 DD  DSN=CAI.ROSLIB01,DISP=OLD
//ROSLIB02 DD  DSN=CAI.ROSLIB02,DISP=OLD
//SYSAWSP  DD  DSN=CAI.AWSP,DISP=OLD
//SYSPRINT DD  SYSOUT=*
/*```

Background:

To help you determine the capacity of the ROSLIBS, ROSTAT gives you 7 numbers.

``` 1.  TOTAL USER DATA SETS         aaa
2.  AVERAGE INDEX CAPACITY       bbb
3.  MAXIMUM INDEX CAPACITY       ccc
4.  MINIMUM INDEX CAPACITY       ddd
5.  TOTAL DATA BLOCKS            eee
6.  TOTAL FREE DATA BLOCKS       fff
7.  TOTAL DEAD DATA BLOCKS       ggg```
1. The TOTAL USER DATA SETS is the total number of members on the ROSLIBS represented above by aaa.
2. The AVERAGE INDEX CAPACITY, is the average number of members in the index. Roscoe calculates this as 1/2 the maximum index capacity. It is represented above by bbb.
3. The MAXIMUM INDEX CAPACITY. (Calculated by multiplying the number of index blocks by the number of entries per block). This value is represented above by ccc.
4. The MINIMUM INDEX CAPACITY. (Calculated by multiplying the number of free index blocks by number of entries per block). This value is represented above by the value ddd.
5. The TOTAL DATA BLOCKS in the Roslibs, represented above by eee
6. The TOTAL FREE DATA BLOCKS (usable) currently in the ROSLIBS, represented by fff
7. The  TOTAL DEAD DATA BLOCKS (unusable) in the ROSLIBS, represented by ggg

Instructions:

• If the TOTAL USER DATA SETS (aaa) is greater than the AVERAGE INDEX CAPACITY (bbb), the index file should be reallocated with a larger index capacity and restored.
• If the MINIMUM INDEX CAPACITY (ccc) is low:
• The TOTAL USER DATA SETS is close to the AVERAGE INDEX CAPACITY, (i.e. If aaa is near bbb) reallocate the index file and restore the libraries.
• The TOTAL USER DATA SETS is 50% of the AVERAGE INDEX CAPACITY, restore the library files from a backup. It does not have to be reallocated. (i.e. If aaa is 50% of bbb, restore the library files.)
• When the TOTAL FREE DATA BLOCKS (fff) is 85% of  the TOTAL DATA BLOCKS (eee), you should either use LIBUTIL,PARM=ADDLIB to add an additional data library, or restore the library to a larger library.
• When the TOTAL DEAD DATA BLOCKS shown above as (ggg) reaches 5% of the TOTAL DATA BLOCKS, (i.e. when ggg is 5% of eee) you should run a LIBUTIL,PARM=RECLAIM.

the index file should be reallocated with a larger index capacity and restored.

or restore the library to a larger library.