Filter
Top Products
I/O Performance and Monitoring Tools 123
Line C in Figure 46 shows BSDS accesses. Just like the active log accesses,
these accesses are mainly writes.
The block of lines starting with
D shows volume of records created in the active
log and offloaded by the archiving process.
The block of lines starting with
E shows archive volume mounting information.
Figure 46. DB2 PM Statistics, Log Activity Section
11.1.3 Performance I/O Information and I/O Activity
DB2 PM can create several I/O activity reports for different types of data sets.
The buffer pool report shows the activity of one identifier (for example: plan, user,
buffer pool id) against the data sets in one virtual buffer pool.
Before the report can be generated, the appropriate trace must be started. It is
recommended to limit the trace to reduce the impact on system performance.
This can be done by specifying class and instrumentation facility componenent
identifiers (IFCIDs) in the START TRACE command. Asynchronous I/O activity is
not collected when user (AUTHID) or application identifiers (PLAN) are specified
in the START TRACE command unless the user identifier of the DBM1 address
space is also listed. Table 26 on page 124 shows the requirements to generate
the trace information for the different I/O activity reports. Figure 47 on page 124
shows an extract from a summary I/O activity report. A detail report allows an
analysis at the identifier level. For example, it can be used for a detailed analysis
of the accesses of one application to one table space.
LOG ACTIVITY QUANTITY /MINUTE /THREAD /COMMIT
--------------------------- -------- ------- ------- -------
READS SATISFIED-OUTPUT BUFF A 0.00 0.00 N/C 0.00
READS SATISFIED-OUTP.BUF(%) N/C
READS SATISFIED-ACTIVE LOG 0.00 0.00 N/C 0.00
READS SATISFIED-ACTV.LOG(%) N/C
READS SATISFIED-ARCHIVE LOG 0.00 0.00 N/C 0.00
READS SATISFIED-ARCH.LOG(%) N/C
TAPE VOLUME CONTENTION WAIT 0.00 0.00 N/C 0.00
WRITE-NOWAIT B 0.00 0.00 N/C 0.00
WRITE OUTPUT LOG BUFFERS 509.00 15.00 N/C 254.50
BSDS ACCESS REQUESTS C 0.00 0.00 N/C 0.00
UNAVAILABLE OUTPUT LOG BUFF 0.00 0.00 N/C 0.00
CONTR.INTERV.CREATED-ACTIVE D 5.00 0.15 N/C 2.50
ARCHIVE LOG READ ALLOCATION 0.00 0.00 N/C 0.00
ARCHIVE LOG WRITE ALLOCAT. 0.00 0.00 N/C 0.00
CONTR.INTERV.OFFLOADED-ARCH 0.00 0.00 N/C 0.00
READ DELAYED-UNAVAIL.RESOUR E 0.00 0.00 N/C 0.00
LOOK-AHEAD MOUNT ATTEMPTED 0.00 0.00 N/C 0.00
LOOK-AHEAD MOUNT SUCCESSFUL 0.00 0.00 N/C 0.00