The SYNCLIST report program executed as part of the normal MFX installation process generates a report that includes a PARASORT report to aid you in creating esoteric unit names for PARASORT.
If you don’t have a copy of the SYNCLIST report on hand, or if you later need to regenerate the PARASORT report for a changed system configuration, simply run the SYNCLIST report program. The following shows sample JCL to execute SYNCLIST:
For more information on SYNCLIST, see SYNCLIST Report Program section described above.
The PARASORT report, which appears in the SYNCLIST report after the “Environmental / Control Block Information” section, provides information in two forms:
- The body of the report is for system programmers. It lists the configuration of the available tape drives along with suggestions for esoteric unit names for each device type and for each type of multiple input (2, 3, or 4 SORTPARn DD statements). The suggested esoteric unit names appear in quotes.
- The conclusion of the report is a table for distribution to PARASORT application programmers. The table displays the exact esoteric unit names that must be used in PARASORT applications.
The report is generated twice, under the headings “PART 1: ONLINE AND OFFLINE DRIVES” and “PART 2: ONLINE DRIVES ONLY.”
The following shows a sample PARASORT report generated by SYNCLIST:
Only the first few lines of Part 2 are shown in the sample report above. Part 2 is identical in format to Part 1. In general, Part 2 will list fewer drives than Part 1, since Part 2 lists only online drives, while Part 1 lists both online and offline drives.
The suggested esoteric unit names are within quotes (for example, “PAR241"). To comply with standards at your site, you may need to use esoteric unit names different from the suggested names.
The PARASORT esoteric unit name definitions ensure the required channel separation in most cases. You assign the indicated device strings to the names as described in STEP 2, below.
Even if all units within a device type already provide sufficient channel separation, it is recommended that you implement the PARASORT esoteric unit names and use them in your PARASORT applications. Doing so will allow you to respond easily to system configuration changes. If you use non-esoteric unit names in the JCL for your PARASORT applications (for example, “3480") and your tape configuration changes, the non-esoteric unit names may no longer provide sufficient channel separation. You would then need to change the JCL for all your PARASORT applications. On the other hand, if you use PARASORT esoteric unit names in all your PARASORT JCL, you don’t have to modify that JCL. Simply change the esoteric unit name definitions. Do this by repeating the 3-step procedure for creating PARASORT esoteric unit names.
If there are insufficient channel paths available to run PARASORT using a particular tape device type, the report will indicate “NOT POSSIBLE” for that device. In certain cases, 4-way input may not be possible, but 3-way or 2-way input may be possible. For instance, there are only two available channel paths for 3590 devices in the sample report. This implies that only a PARASORT with 2-way input (SORTPAR1 DD and SORTPAR2 DD) may be used on those devices. Thus, only two esoteric unit names would need to be defined for 3590 drives.
If you want all tape drives to be available for PARASORT, then use Part 1 of the report, “ONLINE AND OFFLINE DRIVES”. If you want to make only the online drives available for PARASORT, then use only Part 2 of the report, “ONLINE DRIVES ONLY.”
Check that the drives listed in the part of the report you will use are acceptable to you for use by PARASORT. If they are acceptable, skip the following section, “Generating a Customized Report,” and go to STEP 2: Implement the Esoteric Unit Names further in this chapter.
Generating a Customized Report
If you find that the report you want to use lists unacceptable drives, then you must generate a customized report that includes only the acceptable drives. However, you cannot simply drop the unacceptable drives from the esoteric unit name assignments. Doing so may invalidate the desired channel separation. Instead, use the following procedure to generate a new, customized report.
- Rerun SYNCLIST, adding a new PARAOUT DD statement that defines a sequential data
set or a partitioned data set member. A list of all tape drive unit numbers (one
10-byte record for each drive) will be written to PARAOUT, which may have any
DSN. The following shows sample JCL for the PARAOUT DD statement:
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Edit the PARAOUT DD data set or member to remove all drive numbers that are not eligible for PARASORT use. Simply delete the lines containing the drive numbers of ineligible drives. Do not make any other editing changes.
- Change the SYNCLIST JCL so that it will read the PARAOUT DD. To do this, change the
PARAOUT DD to PARAIN. The following example shows JCL for the PARAIN DD statement:
The PARASORT report will be regenerated using only the drives listed in the PARAIN DD statement. The new report will contain only one part since you have specified all the acceptable drives.