Collecting MONWRITE Data:
About as Simple as I Can Make It

This is a simple set of instructions for collecting CP Monitor data via MONWRITE.

The CP Monitor settings cited here are useful for problem diagnosis on small to moderately sized systems:

• MONDCSS is 8192 pages (aka 32 MB)
  • 2048 pages for event data
  • 6144 pages for sample data
    • 3072 pages for sample config records
• All the cool domains are enabled
• Samples every 1 minute

In these instructions, you should skip steps marked (skip) if you are already running a performance monitoring tool such as z/VM Performance Toolkit or some third-party package.

Follow these simple instructions:

1. (skip) Log on to MAINT. Use MAINT to define the MONDCSS segment. These commands will define a 32 MB DCSS (x'2000' aka 8192 pages) at the 160 MB line. After you do these commands, log off of MAINT. CP DEFSEG MONDCSS A000-BFFF SC RSTD CP SAVESEG MONDCSS

2. Log on to MONWRITE.

3. (skip) Let's start with a clean slate for CP Monitor. CP MONITOR STOP

4. (skip) Under MONITOR EVENT, collect all domains except SEEKS and SCHEDULER. CP MONITOR EVENT ENABLE ALL CP MONITOR EVENT DISABLE SEEKS ALL CP MONITOR EVENT DISABLE SCHEDULER ALL

5. (skip) Under MONITOR SAMPLE, collect all domains and set aside 3072 pages for config records. CP MONITOR SAMPLE ENABLE ALL CP MONITOR SAMPLE CONFIG SIZE 3072

6. (skip) Set Monitor's sample intervals. CP MONITOR SAMPLE RATE 1 SEC CP MONITOR SAMPLE INTERVAL 1 MIN

7. (skip) Then start CP Monitor, allowing 2048 pages for event data. CP MONITOR START PARTITION 2048

8. Run MONWRITE. Put the output file on a filemode that has plenty of free space. You will have to figure out which minidisk that is. Let's pretend you looked and discovered filemode B to be the desired target. The example below writes the collected data to file MYDATA MONDATA B. MONWRITE MONDCSS *MONITOR DISK MYDATA MONDATA B

9. After, say, 30 minutes, type MONWSTOP. This stops collection.

10. Package and send us the MONWRITE file. Read here for instructions.