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152 Storage Management with DB2 for OS/390
12.2.2 IXFP View
IXFP builds RVA statistics reports at the level of the storage server: it has a
hardware standpoint, and so consolidates activities from sharing LPARs. This
standpoint also gives to IXFP a good knowledge of data handed into each
channel program. Information on functional volumes mapping to physical disk
space is also available. For the case study, where only one unique query activity
occurred in both the RVA Storage Groups, IXFP information complements the
RMF view.
12.2.2.1 Device Performance Overall Summary
The Figure 72 on page 152 shows an extract of these reports, for both RVAs.
Three items of information confirm that the storage servers are not at their
utilization limit:
•
I/O activity and bandwidth. For each RVA, there are roughly 45 I/Os per
second. This generates a throughput from 5 MB to 5.5 MB per second on each
RVA.
•
Service time. For each RVA, the service time is roughly 30 milliseconds, of
which 25% is disconnect time. Connect times are high, because of the
110-120 KB average size of data transferred per I/O.
•
Net capacity load. The NCL is 56.4% for subsystem 20395 and 29.7% for
subsystem 22897.
Figure 72. Case Study IXFP Device Performance Case Summary Extract
XSA/REPORTER DEVICE PERFORMANCE OVERALL SUMMARY
SUBSYSTEM 20395
SUBSYSTEM % DEV I/O KBYTES ACCESS -I/O SERVICE TIME (MS)- % DEV % DEV % DEV
SUMMARY AVAIL PER SEC PER SEC DENSITY TOTAL DISC CONNECT UTIL DISC CONN
----- ------- ------- ------- ----- ------ ------- ----- ----- -----
PROD PARTITION 100.0 45.7 5481.4 0.1 30.5 7.3 23.3 0.5 0.1 0.4
OVERALL TOTALS 100.0 45.7 5481.4 0.1 30.5 7.3 23.3 0.5 0.1 0.4
SUBSYSTEM 20395 DISK ARRAY SUMMARY
AVG % DRIVE COEFF OF NET CAPACITY LOAD % FREE SPACE COLLECTION LOAD COLL FREE SPC (%) UNCOLL FREE SPC (%)
MODULE UTIL VARIATION TEST PROD OVERALL TEST PROD OVERALL TEST PROD OVERALL TEST PROD OVERALL
---------------------- ----- ----- ------- ----- ----- ------- ----- ----- ------- ----- ----- -------
10.6 78 0.0 56.4 56.4 0.0 0.0 0.0 0.0 42.4 42.4 0.0 1.2 1.2
SUBSYSTEM 22897
SUBSYSTEM % DEV I/O KBYTES ACCESS -I/O SERVICE TIME (MS)- % DEV % DEV % DEV
SUMMARY AVAIL PER SEC PER SEC DENSITY TOTAL DISC CONNECT UTIL DISC CONN
----- ------- ------- ------- ----- ------ ------- ----- ----- -----
PROD PARTITION 100.0 44.5 5036.8 0.1 29.7 7.8 22.0 0.5 0.1 0.4
OVERALL TOTALS 100.0 44.5 5036.8 0.1 29.7 7.8 22.0 0.5 0.1 0.4
SUBSYSTEM 22897 DISK ARRAY SUMMARY
AVG % DRIVE COEFF OF NET CAPACITY LOAD % FREE SPACE COLLECTION LOAD COLL FREE SPC (%) UNCOLL FREE SPC (%)
MODULE UTIL VARIATION TEST PROD OVERALL TEST PROD OVERALL TEST PROD OVERALL TEST PROD OVERALL
---------------------- ----- ----- ------- ----- ----- ------- ----- ----- ------- ----- ----- -------
13.2 86 0.0 25.2 25.2 0.0 0.0 0.0 0.0 73.9 73.9 0.0 0.9 0.9