GPA Manual

Description of GPA Reports
Guardian Performance Analyzer (GPA) Manual—135081
3-4
System Performance Summary
Disk Volume Performance
This subsection of the report (Example 3-2) is a table that indicates the extremes in disk
volume performance for the node. The format is such that the differences in high and
low values can easily be seen as an indication of system performance.
The table identifies, as line items, (1) the least busy and (2) most busy volumes, the
volumes with (3) the lowest and (4) highest request q(ueue) times, the volumes
associated with (5) the least busy and (6) most busy disk processes, and the volumes
with (7) the lowest and (8) highest percentages of cache hits.
For each of these items, the table shows the following data:
(11) AVG DISK VOLUME BUSY: The average percentage busy time of all disk
volumes on the node.
(12) AVG DISK PROCESS BUSY: The average of the percentage busy times of
all disk processes running on the node.
(13) % - RECOMMENDED RESOURCES: The extent to which the node is
being utilized in relation to the maximum recommended (100 percent) level.
The value for this parameter is derived by dividing the AVG CPU BUSY time
(Item 10 above) by the maximum recommended utilization level. For most
CPUs, the maximum recommended utilization level is 60 to 75 percent busy,
depending on the CPU type.
(14) NODE SWAP RATE: The total number of page swaps per second for all of
the processors on the node. Each page swap represents a page (2048 bytes) of
data or code that a processor is forced to transfer from disk to memory. GPA
considers a node swap rate greater than 1 to be excessive and indicates on this
line the cause for such a condition (memory shortage or load imbalance).
Example 3-2. Disk Volume Performance
II. DISK VOLUME PERFORMANCE
9 10 11 12 13 14 15
VOLUME BUSY% REQUEST CPU CACHE REQUEST % OF ALL
QTIME (s) HIT% RATE/SEC CACHE CALL
1
LOW BUSY DISK VOL : $X42 .0 0 2: 3 0.0% 0 0%
2
HI BUSY DISK VOL : $SYSTEM 18.9 25 0: 1 66.1% 12 57%
3
LOW Q-TIME VOL : $ClO 4.2 19 0: 1 90.2% 3 16%
4
HI Q-TIME VOL : $PROJEC .0 114 2: 3 99.7% 1 4%
5
*LOW BUSY DISK PROC: $B40 .1 0 0: 1 0.0% 0 0%
6
*HI BUSY DISK PROC: $SYSTEM 7.2 25 0: 1 66.1% 12 57%
7
*LOW CACHE PERF. : $XPRESS 1.7 51 2: 3 52.6% 0 4%
8
*HI CACHE PERF. : $NSMS 6.3 24 2: 3 99.9% 4 20%
(* relates to the disk process. request-qtime is expressed in Ms).
(9) VOLUME: The volume name.
(10) BUSY%: Percentage of time the volume or disk process is busy.
(11) REQUEST QTIME: The request queue time, which is the interval (in
milliseconds) between the time a disk process receives a request and the time it
finishes processing the request.