Post-Install Optimizations: Difference between revisions
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=== (Memory) Allocation === | === (Memory) Allocation === | ||
* Adjust automatic performance values only at runtime, not at IPL. | * Adjust automatic performance values only at runtime, not at IPL.<ref>If you change the mount of memory for the machine, could be wise to adjust the value to '1', make the memory change and then change the value back to '3'.</ref> | ||
CHGSYSVAL SYSVAL(QPFRADJ) VALUE('3') | CHGSYSVAL SYSVAL(QPFRADJ) VALUE('3') | ||
* Make sure, database tasks can use system resources as needed. | * Make sure, database tasks can use system resources as needed. |
Revision as of 09:52, 9 September 2020
OS/400 provides a lot of default values for variables (affecting the run-time environment) and program options. Some of these make sense, some of them are kept consistent with earlier versions of the OS because of compatibility reasons by IBM.
Some of these recommendations might not be appropriate for you by various reasons. Don't apply blindly. Know what you do, use the online help to retrieve background information on the topic in question.
The findings below are based on V4R5 with annotated exceptions for newer releases.
Housekeeping
These are settings and scheduled jobs to keep your system uncluttered.
Change unneeded programs to not run
We most likely don't need to run lpd and smtpd to run per default.
CHGLPDA AUTOSTART(*NO) CHGSMTPA AUTOSTART(*NO)
You can easily check all settings at once by using STRDFU OPTION(5)
on the file QUSRSYS/QATOCSTART. These are not needed in general. Depending on OS version, not all entries may be available.
- *DIRSRV
- *NETSVR
- *SLP
Cleanup unneeded stuff
These objects come by default at OS install time, are not needed to my knowledge, and thus can be safely deleted:
DLTOUTQ OUTQ(QDKT) DLTOUTQ OUTQ(QPFROUTQ) DLTOUTQ OUTQ(QPRINTS) DLTF FILE(QPRINTS) DLTOUTQ OUTQ(QPRINT2) DLTF FILE(QPRINT2) DLTOUTQ OUTQ(QTPPPOUTQ) DLTDEVD DEVD(QESPAP) DLTDEVD DEVD(QIADSP) DLTDEVD DEVD(QIAPRT) DLTDEVD DEVD(QQAHOST) DLTDEVD DEVD(QTIDA) DLTDEVD DEVD(QTIDA2) DLTCTLD CTLD(QESCTL) DLTCTLD CTLD(QTICTL) DLTLIND LIND(QESLINE) DLTLIND LIND(QTILINE)
System Values
System values are like environment variables as known from common operating systems. They influence system operation. I recommend the following changes.
System Control
- Change work environment to separate subsystems for different kind of jobs.
CHGSYSVAL SYSVAL(QCTLSBSD) VALUE('QCTL QSYS')
- Set automatic DST adjustment, and UTC offset. This value is valid for Central Europe (Berlin, Paris, …) and not available in V4R5.
CHGSYSVAL SYSVAL(QTIMZON) VALUE('QP0100CET2')
- Lessen time to automatically end disconnected interactive jobs (sessions).
CHGSYSVAL SYSVAL(QDSCJOBITV) VALUE('60')
(Memory) Allocation
- Adjust automatic performance values only at runtime, not at IPL.[1]
CHGSYSVAL SYSVAL(QPFRADJ) VALUE('3')
- Make sure, database tasks can use system resources as needed.
CHGSYSVAL SYSVAL(QQRYDEGREE) VALUE(*OPTIMIZE)
- Match jobs running in total with reservations at IPL time. See
WRKACTJOB
and set to slightly more than the Active Jobs value to be seen there.
CHGSYSVAL SYSVAL(QTOTJOB) VALUE(80)
- Allow memory pools to self adjust depending on jobs running. You can adjust the maximum active jobs per pool in the
WRKSHRPOOL
display.[2]
CHGSHRPOOL POOL(*BASE) PAGING(*CALC) CHGSHRPOOL POOL(*INTERACT) PAGING(*CALC) CHGSHRPOOL POOL(*SPOOL) PAGING(*CALC)
Message-and-Logging
- Allow immediate deletion of problem reports.
CHGSYSVAL SYSVAL(QPRBHLDITV) VALUE(0)
- Do not log software errors. We can't do much about these anyway, seen from a hobbyist viewpoint.
CHGSYSVAL SYSVAL(QSFWERRLOG) VALUE(*NOLOG)
- Maximize Central Syslog (viewable with
DSPLOG
size before rotation. Depending on OS version only VALUE(32767) may be valid.
CHGSYSVAL SYSVAL(QHSTLOGSIZ) VALUE(*DAILY)
- Raise allowed unsuccessful sign on tries before taking action.
CHGSYSVAL SYSVAL(QMAXSIGN) VALUE('15')
- Minimize logging for sessions disconnected beause of device errors.
CHGSYSVAL SYSVAL(QDEVRCYACN) VALUE(*ENDJOBNOLIST)
Security System Values
- Unrestrict automatic creation of system objects triggered by external (network) requests.
CHGSYSVAL SYSVAL(QAUTOVRT) VALUE(*NOMAX)
- Allow restore with all security relevant flags.
CHGSYSVAL SYSVAL(QALWOBJRST) VALUE(*ALL)
- Allow QSYSOPR signon to all devices.
CHGSYSVAL SYSVAL(QLMTSECOFR) VALUE('0')
- Raise maximum password length to maximum value.[3]
CHGSYSVAL SYSVAL(QPWDMAXLEN) VALUE(10)
- Raise minimum passsword length for security reasons.
CHGSYSVAL SYSVAL(QPWDMINLEN) VALUE(8)
Misc
- PTF install shall be done on unattended IPL time.
CHGSRVA PTFINSTYP(*DLYALL)
- Provide European style formatting.
CHGSYSVAL SYSVAL(QCURSYM) VALUE('€') CHGSYSVAL SYSVAL(QDECFMT) VALUE('J') CHGSYSVAL SYSVAL(QSRTSEQ) VALUE(*LANGIDUNQ)
- Allow background compiling in PDM.
GRTOBJAUT OBJ(QGPL/QBATCH) OBJTYPE(*JOBD) USER(*PUBLIC) AUT(*USE)
- Tweaking automatic cleanup (like logrotate).
CHGCLNUP ALWCLNUP(*YES) STRTIME('02:22:22') USRMSG(7) SYSMSG(3) SYSPRT(7) SYSLOG(14) CALITM(*KEEP)
- Change general SNA networking attributes. This is one long line. Take care to get it completely.
CHGNETA ALRSTS(*ON) ALRLOGSTS(*LOCAL) ALRPRIFP(*NO) ALRDFTFP(*NO) ALRBCKFP(*NONE) ALRRQSFP(*NONE) ALRCTLD(*NONE) ALRHLDCNT(0) ALRFTR(*NONE) JOBACN(*SEARCH) VRTAUTODEV(254) MDMCNTRYID(DE)
IPL Customization
With this procedure, the current startup program for the OS can be retrieved for easy customization.
RTVCLSRC PGM(QSTRUP) SRCFILE(QCLSRC) WRKMBRPDM FILE(QCLSRC) MBR(QSTRUP) MBRTYPE(CLP) CRTCLPGM PGM(QSYS/QSTRUP)
Change Program Defaults
- File creation and change defaults.
CHGCMDDFT CMD(CRTPF) NEWDFT('SIZE(*NOMAX *N *N) WAITFILE(*IMMED) WAITRCD(*IMMED) REUSEDLT(*YES)') CHGCMDDFT CMD(CHGPF) NEWDFT('DLTDEPLF(*YES) SIZE(*NOMAX *N *N) WAITFILE(*IMMED) WAITRCD(*IMMED) REUSEDLT(*YES)') CHGCMDDFT CMD(CRTLF) NEWDFT('WAITFILE(*IMMED) WAITRCD(*IMMED)') CHGCMDDFT CMD(CHGLF) NEWDFT('WAITFILE(*IMMED) WAITRCD(*IMMED)')
- No unnecessary wait for power down.
CONFIRM(*NO)
can be added for newer releases to suppress prompting.
CHGCMDDFT CMD(PWRDWNSYS) NEWDFT('OPTION(*IMMED) ENDSBSOPT(*NOJOBLOG)')
Regular Cleanup jobs
See job comment TEXT for details. These are long lines. Take care to get it completely.
ADDJOBSCDE JOB(PRGPRB) CMD(DLTPRB STATUS(*CLOSED)) FRQ(*WEEKLY) SCDDATE(*NONE) SCDDAY(*ALL) SCDTIME('13:22:00') MSGQ(*LIBL/QSYSOPR) TEXT('Purge closed and deletable problem entries') ADDJOBSCDE JOB(RCLTMPSTG) CMD(RCLTMPSTG DAYS(30)) FRQ(*MONTHLY) SCDDATE(*MONTHSTR) SCDDAY(*NONE) SCDTIME('13:24:00') MSGQ(*LIBL/QSYSOPR) TEXT('Reclaim temporary storage') ADDJOBSCDE JOB(RTVDSKINF) CMD(RTVDSKINF) FRQ(*MONTHLY) SCDDATE(*MONTHSTR) SCDDAY(*NONE) SCDTIME('13:34:00') MSGQ(*LIBL/QSYSOPR) TEXT('Retrieve disk space stats') ADDJOBSCDE JOB(QPGMRCLR) CMD(CLRMSGQ MSGQ(QPGMR) CLEAR(*KEEPUNANS)) FRQ(*WEEKLY) SCDDATE(*NONE) SCDDAY(*ALL) SCDTIME('07:07:07') RCYACN(*NOSBM) MSGQ(*NONE) TEXT('Delete uninteresting messages')
See also
Footnotes
- ↑ If you change the mount of memory for the machine, could be wise to adjust the value to '1', make the memory change and then change the value back to '3'.
- ↑ Press
F21
to switch to view 2 or 3 to have adjustment possibilities. - ↑ In newer OS versions, an additional variable QPWDLVL allows even longer passwords.