Routine maintenance

This chapter is the list of things to look at when nothing is happening: PTFs, IPLs, disk space, system values and schedules.

Fixes: PTFs

Fixes are called PTFs (Program Temporary Fixes). IBM ships them singly, collected in the cumulative package, and in groups by area: Db2, HIPER (High Impact PERvasive), Java, security and others. Each group has a progressive level, and that is what you follow.

WRKPTFGRP

In SQL, the highest installed level of each group:

SELECT PTF_GROUP_NAME, MAX(PTF_GROUP_LEVEL) AS LIVELLO
  FROM QSYS2.GROUP_PTF_INFO
 WHERE PTF_GROUP_STATUS = 'INSTALLED'
 GROUP BY PTF_GROUP_NAME
 ORDER BY PTF_GROUP_NAME

It follows IBM's example for the view, which finds the cumulative level with MAX(PTF_GROUP_LEVEL) and PTF_GROUP_STATUS = 'INSTALLED'. Reading it needs *USE to the WRKPTFGRP command. Compare the level with the current one IBM publishes for your release.

Now or at the next IPL

Some PTFs cannot be applied at once, because the operating system or products they affect are active: these are delayed PTFs, applied only at the next IPL. Immediate PTFs are applied without an IPL, if the objects they affect are not in use and all requisite PTFs can be applied immediately too. DSPPTFAPYI tells you in advance how it will go.

Groups waiting for an IPL:

SELECT PTF_GROUP_NAME, PTF_GROUP_LEVEL
  FROM QSYS2.GROUP_PTF_INFO
 WHERE PTF_GROUP_STATUS = 'APPLY AT NEXT IPL'

The IPL

A restart is called an IPL (Initial Program Load).

PWRDWNSYS OPTION(*CNTRLD) DELAY(600) RESTART(*YES)

With *CNTRLD the subsystems end jobs in a controlled way within the DELAY time (3600 seconds by default), and programs do their end-of-job processing; whatever is left after that is ended immediately.

The IPL side: A and B

The system keeps two copies of the Licensed Internal Code. Copy A is the permanent one; B also holds the Licensed Internal Code fixes applied temporarily. B is the one normally used, and is needed for temporary fixes to take effect; IBM points to A when an IPL from B fails because of one of them.

DSPPTF LICPGM(5770999)

In the "IPL source" field, ##MACH#A is A and ##MACH#B is B. The side is chosen with PWRDWNSYS ... IPLSRC(A) or IPLSRC(B), from the control panel (function 02, together with the mode: manual or normal) or, for a partition, from the HMC.

Disk space

The number to watch is the system ASP's occupancy against its threshold: 90% by default, beyond which the system starts sending messages. What happens next, and the QSYS2.ASP_INFO query with the threshold next to the occupancy, are in the chapter on ASPs.

WRKSYSSTS

Per disk unit:

SELECT UNIT_NUMBER, UNIT_TYPE,
       DEC(PERCENT_USED, 5, 1) AS PERCENTUALE
  FROM QSYS2.SYSDISKSTAT
 ORDER BY PERCENT_USED DESC

Where the space goes is covered by the chapters on the spool and on saving, for journal receivers.

System values

They are the machine's global settings.

WRKSYSVAL
DSPSYSVAL SYSVAL(QSECURITY)

Those this guide has already named:

All of them, with the shipped value alongside:

SELECT SYSTEM_VALUE_NAME, SYSTEM_VALUE, SHIPPED_DEFAULT_VALUE
  FROM QSYS2.SYSTEM_VALUE_INFO
 ORDER BY SYSTEM_VALUE_NAME

Schedules

The system has its own scheduler:

WRKJOBSCDE
ADDJOBSCDE JOB(CHIUSURA) CMD(CALL PGM(PRODLIB/CHIUSURA)) +
           FRQ(*MONTHLY) SCDDATE(*MONTHEND) SCDTIME(230000)

SELECT SCHEDULED_JOB_NAME, STATUS, DESCRIPTION
  FROM QSYS2.SCHEDULED_JOB_INFO
 WHERE STATUS = 'HELD'

What to look at, and how often

A starting point, to be adapted to the installation:

Each item is a query or a command, and almost all can be run from a scheduler entry.

Sources

• IBM: GROUP_PTF_INFO view
• IBM: Applying fixes
• IBM: Power Down System (PWRDWNSYS)
• IBM: Determining the storage area before installing fixes
• IBM: Changing operating modes and IPL types
• IBM: SYSDISKSTAT view
• IBM: SYSTEM_VALUE_INFO view
• IBM: Add Job Schedule Entry (ADDJOBSCDE)
• IBM: SCHEDULED_JOB_INFO view