Disk subprocess analysis and recommendations – HP Integrity NonStop J-Series User Manual
Page 93
Guardian Performance Analyzer (GPA) User Guide
– (544541-006) Page 93 of 131
Disk Subprocess Analysis and Recommendations
GPA generates an analysis of the disk subprocesses like the one shown in Example
4-16. This section of the standard report enables you to see the number of disk
subprocesses allocated to each logical disk volume. GPA makes recommendations to
add subprocesses when it finds that they are highly active. Making actual changes to
the number of disk subprocesses is done by performing a new SYSGEN or using SCF.
Before making these changes, you should double-check that the disk processing that
occurred during the measurement period is typical for your system. For example, you
might confirm that GPA shows the same recommendations over more than one 24-
hour measurement period where the disk processing appears to be typical.
The figure shows that all of the logical volumes in the system are configured with eight disk
subprocesses (PINs) except $DMP10, which has six. (The maximum that can be
configured is eight.) As you look at the figure, pay attention to the recommended
change column. This column shows the recommended change to the number of disk
subprocesses (i.e. Pins) configured. In the case of $DMP10, the RE Q QTIME AQL
has a FAIR rate in accordance to the following Rating Criteria (
GOOD (AQL < 1.0); FAIR
(1.0 <= AQL <= 3.0); POOR (AQL > 3.0)
). GPA therefore recommends that an additional PIN
be allocated to this particular volume.
Example 4-16. Disk Subprocess Analysis and Recommendations
DISK SUBPROCESS ANALYSIS AND RECOMMENDATIONS RATING
CRITERIA: GOOD (AQL < 1.0); FAIR (1.0 <= AQL <= 3.0); POOR (AQL > 3.0)
LOGICAL DP RCM
DISK II REQ NEW
VOLUME PINS REQUEST QTIME DEFREQ DEFER REQUEST DEVICE RCM PIN
NAME CNFG QTIME AQL QTIME QTIME ART AST RATE CHG CNFG
-------- ---- -------- ------ -------- -------- -------- -------- ---- --- ----
$AUD01 8 23190.32 0.26 0.00 0.00 2.47 2.83 GOOD 8
$DMP10 6 93773.53 1.09 0.00 0.00 50.48 4.04 FAIR 1 7
$MD003 8 47695.81 0.55 19927.89 18557.51 0.79 3.91 GOOD 8