Post on 07-Apr-2015
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Chapter 13
Subsystems
Understanding AS/400 System Operations 2
Basic Facts All work is carried out
in a subsystem. All jobs are divided by
type into subsystems. Subsystems are
started when the AS/400 powers up and loads the Operating System.
A way of organizing, in order to increase efficiency.
J
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OFFICE
Understanding AS/400 System Operations 3
Memory: Activity Levels
Activity levels -enhance raw memory allocation by restricting how many programs will vie for the same memory at the same time.
Understanding AS/400 System Operations 4
Why limit activity level? Each job secures enough resources
to run efficiently Too large of a number will force
jobs to compete for system resources and ultimately slow completion of all jobs
Understanding AS/400 System Operations 5
Memory: Storage Pools
A storage pool is a pool of memory where one type of program or application (a set of programs) runs.
Understanding AS/400 System Operations 6
Subsystems Are: A subsystem is an environment
unique to a type of program. It allows computer run-time attributes to be applied to all jobs within it, while other jobs in other subsystems keep their own attributes.
Understanding AS/400 System Operations 7
Single Vs. Multiple Subsystem Configuration
Single - QBASE The subsystem for
all work active upon installation
Convenient for installation
Doesn’t take advantage of system’s capabilities
Multiple Improves performance
to separate workload AS/400 comes
preloaded with basic 5 subsystems
Change system value for QCTLSBSD to QCTL & the AS/400 understands to start using multiple subsystems
Understanding AS/400 System Operations 8
5 Basic Subsystems QCTL
the controlling subsystem in a multiple subsystem configuration
The system console is attached to this subsystem
This is so the system console can carry out functions during IPL
Understanding AS/400 System Operations 9
5 Basic Subsystems (cont.) QINTER
Subsystem that supports interactive jobs
QSPL Handles all spooled file jobs
Understanding AS/400 System Operations 10
5 Basic Subsystems (cont.) QCMN
Supports all communications jobs QBATCH
Supports all batch jobs
Understanding AS/400 System Operations 11
5 Basic Subsystems (cont.) The AS/400 allows for any
combination of jobs within a subsystem. However, doing so will reduce the system’s efficiency.
The object, subsystem description, is required whenever a new subsystem is created.
Understanding AS/400 System Operations 12
System Pools Also called a storage pool. A logical division of main memory
reserved for processing jobs. Subsystems are pre-assigned to
main memory pools by the Operating System.
Work is divided into types of jobs (Just like types of pools).
Understanding AS/400 System Operations 13
Storage Pool Characteristics Activity Level
Max number of jobs that can be run simultaneously in the poolHow many lanes
Pre-defined size number of bytes
that can be stored in the pool How much water
Understanding AS/400 System Operations 14
Shipped Storage Pools *MACHINE is the storage pool
where the system runs. *BASE can be where everything
else runs.
Understanding AS/400 System Operations 15
Related System Values QMCHPOOL - Sets Size OF
*Machine pool. QBASPOOL - Sets minimum size of
*BASE pool.
Understanding AS/400 System Operations 16
Portion of Memory
A pool is the amount of allocated memory.
Understanding AS/400 System Operations 17
Memory Management Concepts Paging is writing a inactive
memory page to DASD so an active page can be read into memory.
Faulting is when a program (or its data) attempts to access a page not in memory. It then is fetched.
Understanding AS/400 System Operations 18
Memory Management Concepts Timeslice, is the period of
time allocated for CPU usage by a job when it executes.
Thrashing is excessive faulting.
Understanding AS/400 System Operations 19
CPU Considerations Time Slices
The amount of processor time a job has before the CPU moves to another job
Run Priorities Within a storage pool, job with highest
prior acquires system resources first Ex: Print writers, then interactive jobs,
then batch jobs
Understanding AS/400 System Operations 20
CPU Considerations (cont.) Run Priority Vs. Job Priority
Run priority is the priority of job while executing
Job priority is the relative order of job waiting on job queue
Understanding AS/400 System Operations 21
AS/400 Jobs Three States Active—The job is running. Job is
occupying storage, using processor, and hasn’t exceeded activity level.
Wait—The job is waiting for something to happen. Waiting until next user request to start.
Ineligible— The job is ready to run, but the system is not available. Ineligible job can’t occupy storage or processor due to activity level is at max.
Understanding AS/400 System Operations 22
AS/400 Jobs Three States (cont.) Jobs shift between states
automatically, depending on system’s work load
Job may need to become ineligible at end of its time slice
Understanding AS/400 System Operations 23
Memory Pool Types Shared Pools
Special shared pools. The two pools that come with the AS/400, *MACHINE and *BASE, are special shared pools. These are the only special shared pools.
General shared pools. Private Pools
Maximum pools = 64 including *BASE and *MACHINE.
Understanding AS/400 System Operations 24
Pre-defined Pools The AS/400 comes with predetermined
names and, in two cases, predetermined uses, for shared pools.
Here is the list: *INTERACT —Supports interactive
subsystems’ jobs. *SPOOL—Supports spool writers (printing). *SHRPOOL1 through *SHRPOOL60— Names
available for customer-defined shared pools.
Understanding AS/400 System Operations 25
Creating Private Pools/ Assigning Shared Pools
Create Subsystem Description (CRTSBSD) Type choices, press Enter. Subsystem description . . . . . _______ Name Library . . . . . . . . . . . *CURLIB Name, *CURLIB Storage pools: ___ Pool identifier . . . . . . . _________ 1-10 Storage size . . . . . . . . . _________ Number, *BASE, *NOSTG... Activity level . . . . . . . . _______ Number + for more values _________ Maximum jobs . . . . . . . . . . *NOMAX 0-1000, *NOMAX Text 'description' . . . . . . . *BLANK Bottom F3=Exit F4=Prompt F5=Refresh F10=Additional parameters F12=Cancel F13=How to use this display F24=More keys
Understanding AS/400 System Operations 26
Changing Pool Memory/ Activity Levels Three commands that change
memory and activity level settings on pools.
They are: Work with System Status (WRKSYSSTS) Change Subsystem Description
(CHGSBSD) Change Shared Pool (CHGSHRPOOL)
Understanding AS/400 System Operations 27
Changing Pool Memory/ Activity Levels (cont.) There are also two system values
that affect memory pools and activity levels: Machine Pool (QMCHPOOL) Base Activity Level (QBASACTLVL)
Understanding AS/400 System Operations 28
Table 13-1: Memory Activity Level Commands
Pool Name Adjustments to Memory
Adjustments to Activity Level
*MACHINE QMCHPOOL (sv) WRKSYSSTS
—— n/a ——
*BASE —— n/a —— QBASACTLVL (sv) WRKSYSSTS
ALL PRIVATE POOLS
WRKSYSSTS CHGSBSD
WRKSYSSTS CHGSBSD
ALL SHARED POOLS
WRKSYSSTS CHGSHRPOOL
WRKSYSSTS CHGSHRPOOL
(sv) = System Value. Use CHGSYSVAL command to change these.
Understanding AS/400 System Operations 29
CHGSHRPOOL command Change Shared Storage Pool (CHGSHRPOOL) Type choices, press Enter. Pool identifier . . . . . . . . __________ *MACHINE, *BASE, *INTERACT... Storage size . . . . . . . . . . *SAME Number, *SAME, *NOSTG Activity level . . . . . . . . . *SAME Number, *SAME Paging option . . . . . . . . . *SAME *SAME, *FIXED, *CALC Text 'description' . . . . . . . *SAME ____________________________________________________________________________ Bottom F3=Exit F4=Prompt F5=Refresh F10=Additional parameters F12=Cancel F13=How to use this display F24=More keys
Figure 13-2: CHGSHRPOOL command
Understanding AS/400 System Operations 30
Private Pools Changed Within Subsystems
Change Subsystem Description (CHGSBSD) Type choices, press Enter. Subsystem description . . . . . > QINTER Name Library . . . . . . . . . . . *LIBL Name, *LIBL, *CURLIB Storage pools: __ Pool identifier . . . . . . . *SAME 1-10, *SAME Storage size . . . . . . . . . _________ Number, *BASE, *NOSTG... Activity level . . . . . . . . _________ Number + for more values Maximum jobs . . . . . . . . . . *SAME 0-1000, *SAME, *NOMAX Text 'description' . . . . . . . *SAME ___________________________________________________________________________ Bottom F3=Exit F4=Prompt F5=Refresh F10=Additional parameters F12=Cancel F13=How to use this display F24=More keys
Figure 13-3: CHGSBSD command to change private pool sizes.
Understanding AS/400 System Operations 31
Work with Subsystems (WRKSBS)
Work with System Status System: BIGBLUE Type options, press Enter. 4=End subsystem 5=Display subsystem description 8=Work with subsystem jobs Subsystem Pool 1 Subsystem Pool 2 Total -----------Subsystem Pools------------ Opt Subsystem Storage (K) 1 2 3 4 5 6 7 8 9 10 _ QBASE 0 2 3 _ QBATCH 0 2 _ QCMN 0 2 _ QCTL 0 2 _ QINTER 0 2 3 System Pool 3 _ QCOMPILE 0 2 11 System Pool 11 _ QSERVER 0 2 _ QSPL 0 2 4 _ QSYSSBSD 0 2 _ QSYSWRK 0 2 System Pool 2 Bottom Parameters or command ===>_________________________________________________________________ F3=Exit F5=Refresh F11=Display system data F12=Cancel F14=Work with system status
Understanding AS/400 System Operations 32
WRKSBS – Display Pool Definitions
Display Pool Definitions
System: BIGBLUE Subsystem description: QCOMPILE Status: ACTIVE Pool Storage Activity ID Size (K) Level 1 *BASE 2 *SHRPOOL2 Shared Pool Names Subsystem Pool Number Bottom Press Enter to continue. F3=Exit F12=Cancel
Figure 13-5: Command WRKSBS, displaying pool definitions.
Understanding AS/400 System Operations 33
Work with System Status
Work with System Status BIGBLUE 07/05/99 12:06:24
% CPU used . . . . . . : 63.0 Auxiliary storage: Elapsed time . . . . . : 00:30:01 System ASP . . . . . : 22357 M Jobs in system . . . . : 9789 % system ASP used . : 71.4165 % addresses used: Total . . .. . . . . : 187375 M Permanent . . . . . : 22.313 Current unprotect used: 2854 M Temporary . . . . . : 4.707 Maximum unprotect . : 3222 M Type changes (if allowed), press Enter. System Pool Reserved Max -----DB----- ---Non-DB--- Pool Size (K) Size (K) Active Fault Pages Fault Pages 11 50000 0 4 .0 .3 2.7 .0 System Pool Number Bottom Command ===>___________________________________________________________ F3=Exit F4=Prompt F5=Refresh F9=Retrieve F10=Restart F11=Display transition data F12=Cancel F24=More keys
Figure 13-6: Command WRKSYSSTS, information about system pools.
Understanding AS/400 System Operations 34
Work Shared PoolsWork Shared Pools
System: BIGBLUE Main storage size (K) . : 655360
Type changes (if allowed), press Enter.
Defined Max Allocated Pool -Paging Option-- Pool Size (K) Active Size (K) ID Defined Current *MACHINE 90000 +++++ 90000 1 *FIXED *FIXED *BASE 88360 32 88360 2 *FIXED *FIXED *INTERACT 10000 7 10000 8 *FIXED *FIXED *SPOOL 12000 7 12000 3 *FIXED *FIXED *SHRPOOL1 200000 10 200000 4 *CALC *CALC *SHRPOOL2 50000 4 50000 11 *FIXED *FIXED *SHRPOOL3 50000 4 50000 10 *CALC *CALC *SHRPOOL4 40000 10 40000 5 *FIXED *FIXED *SHRPOOL5 70000 7 70000 6 *FIXED *FIXED *SHRPOOL6 0 0 0 *FIXED More... Command ===>____________________________________________________________________ F3=Exit F4=Prompt F5=Refresh F9=Retrieve F11=Display tuning data F12=Cancel
Figure 13-7: Command WRKSHRPOOL.
Understanding AS/400 System Operations 35
Subsystem Description Create Subsystem Description (CRTSBSD) Type choices, press Enter. Subsystem description . . . . NEWSBS Name Library . . . . . . . . . . *CURLIB Name, *CURLIB Storage pools: _ Pool identifier . . . . . . 2 1-10 Storage size . . . . . . . . *BASE Number, *BASE, *NOSTG... Activity level . . . . . . . Number + for more values Maximum jobs . . . . . . . . . 4 0-1000, *NOMAX Text 'description' . . . . . . *BLANK ______________________________________________________________________ Additional Parameters Sign-on display file . . . . . *QDSIGNON Name, *QDSIGNON Library . . . . . . . . . . ________ Name, *LIBL, *CURLIB Subsystem library . . . . . . *NONE Name, *NONE More... F3=Exit F4=Prompt F5=Refresh F12=Cancel F13=How to use this display F24=More keys
Figure 13-8: Prompted CRTSBSD command.
Understanding AS/400 System Operations 36
Add Storage Pools to Subsystem Specify More Values for Parameter POOLS Type choices, press Enter. Storage pools: Pool identifier . . . . . . > 2 1-10 Storage size . . . . . . . . *BASE Number, *BASE, *NOSTG... Activity level . . . . . . . ________ Number Pool identifier . . . . . . 11 1-10 Storage size . . . . . . . . 50000 Number, *BASE, *NOSTG... Activity level . . . . . . . 4 Number Pool identifier . . . . . . 1-10 Storage size . . . . . . . . Number, *BASE, *NOSTG... Activity level . . . . . . . Number Pool identifier . . . . . . 1-10 Storage size . . . . . . . . Number, *BASE, *NOSTG... Activity level . . . . . . . Number More... F3=Exit F4=Prompt F5=Refresh F12=Cancel F13=How to use this display F24=More keys
Figure 13-9: Adding storage pools to a new subsystem description
Understanding AS/400 System Operations 37
Routing Entries Display Job Description System: BIGBLUE Job description: QINTER Library: QGPL Message logging: Level . . . . . . . . . . . . . . . . . . . . : 4 Severity . . . . . . . . . . . . . . . . . . . : 0 Text . . . . . . . . . . . . . . . . . . . . . : *NOLIST Log CL program commands . . . . . . . . . . . . : *NO Accounting code . . . . . . . . . . . . . . . . : *USRPRF Print text . . . . . . . . . . . . . . . . . . . : *SYSVAL Routing data . . . . . . . . . . . . . . . . . . : QCMDI
Figure 13-10: A sample of the routing data for a job description.
Understanding AS/400 System Operations 38
Routing Entries (cont.) Display Routing Entries System: BIGBLUE Subsystem description: QINTER Status: ACTIVE Type options, press Enter. 5=Display details Start Opt Seq Nbr Program Library Compare Value Pos _ 10 QCMD QSYS 'QCMDI' 1 _ 20 QCMD QSYS 'QS36MRT' 1 _ 40 QARDRIVE QSYS '525XTEST' 1 _ 700 QCL QSYS 'QCMD38' 1 _ 9999 QCMD QSYS *ANY Bottom F3=Exit F9=Display all detailed descriptions F12=Cancel
Figure 13-11: Routing entries in the subsystem description.
Understanding AS/400 System Operations 39
Routing Entries (cont.) Display Routing Entry Detail System: BIGBLUE Subsystem description: QINTER Status: ACTIVE Routing entry sequence number . . . . . . . : 10 Program . . . . . . . . . . . . . . . . . . : QCMD Library . . . . . . . . . . . . . . . . . : QSYS Class . . . . . . . . . . . . . . . . . . . : QPTY35 Library . . . . . . . . . . . . . . . . . : QGPL Maximum active routing steps . . . . . . . : *NOMAX Pool identifier . . . . . . . . . . . . . . : 2 Compare value . . . . . . . . . . . . . . . : 'QCMDI' Compare start position . . . . . . . . . . : 1 Press Enter to continue. F3=Exit F12=Cancel F14=Display previous entry
Figure 13-12: Expanded routing entries in the subsystem description.
Understanding AS/400 System Operations 40
Workstation Entries AS/400 workstations are devices
(Interactive Jobs Only) Job Queues Autostart Jobs Communication Jobs Pre-start Jobs
Understanding AS/400 System Operations 41
Starting Subsystems Start Subsystem (STRSBS) Type choices, press Enter. Subsystem description . . . Name Library . . . . . . . . . *LIBL Name, *LIBL, *CURLIB Bottom F3=Exit F4=Prompt F5=Refresh F12=Cancel F13=How to use this display F24=More keys
Figure 13-13: Prompted STRSBS command.
Understanding AS/400 System Operations 42
Ending Subsystems End Subsystem (ENDSBS) Type choices, press Enter. Subsystem . . . . . . . . . . . > QBATCH Name, *ALL How to end . . . . . . . . . . . *CNTRLD *CNTRLD, *IMMED Delay time, if *CNTRLD . . . . . *NOLIMIT Seconds, *NOLIMIT Bottom F3=Exit F4=Prompt 5=Refresh F10=Additional parameters F12=Cancel F13=How to use this display F24=More keys
Figure 13-14: Prompted ENDSBS command.
Understanding AS/400 System Operations 43
Basic Work Management Structure
Understanding AS/400 System Operations 44