Device Summary (PI_DEVS)
- Organization of this page
Function
The Device Summary (PI_DEVS) record stores the performance data in which the data stored in the Device Detail (PI_DEVD) record is summarized per unit time. Note that even if the Device Detail (PI_DEVD) record is not collected, performance data is stored in the Device Summary (PI_DEVS) record.
- Notes:
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In Linux, the performance data of only the devices that have the following major numbers are collected from /proc/partitions and summarized in the Device Summary (PI_DEVS) record: 3, 8, 22, 33, 34, 56, 57, 65 to 71, 88 to 91, and 128 to 135
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If the DR function of Solaris is used to modify a system resource while a PFM - Agent for Platform service is running, some types of performance data cannot be correctly collected. The table below shows the types of system resources that are affected and the actions that you can take to correctly display reports after the modification.
System resource type
Report type
Actions to be taken after modification
Device
Real-time
Display the report again.
Historical
Specify the display period such that it does not include the date and time when the system resources were modified.
Fields other than those listed below are affected by a system resource modification:
• Interval (INTERVAL)
• Record Time (RECORD_TIME)
• Record Type (INPUT_RECORD_TYPE)
• Fields that are added only when data is recorded in the Store database
For details about modifying system resources, see Notes on performance information when modifying system resources in Notes on records
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Only the local disk devices of Persistent DSF are collected in HP-UX.
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Default values and values that can be specified
|
Item |
Default value |
Modifiable |
|---|---|---|
|
Collection Interval |
60 |
Yes |
|
Collection Offset |
0 |
Yes |
|
Log |
No |
Yes |
|
LOGIF |
Blank |
Yes |
|
Over 10 Sec Collection Time |
No |
No |
|
Realtime Report Data Collection Mode |
Reschedule |
Yes |
ODBC key fields
None
Lifetime
None
Record size
-
Fixed portion: 1,069 bytes
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Variable portion: 0 bytes
Fields
|
PFM-View name (PFM-Manager name) |
Description |
Smry |
Format |
Delta |
Not sprtd in |
Data source |
|---|---|---|---|---|---|---|
|
Avg Service Time/device(SERVICE_TIME) |
Average service time per device (seconds). In HP-UX, this value indicates the total service time of all I/Os, and therefore, it may significantly exceed the value of Interval when processes are continuously executed on a device. Even with other OSs, the value may exceed the value of Interval when processes are continuously executed on a device. |
AVG |
utime |
No |
-- |
TOTAL_SERVICE_TIME ÷ DEVICE_COUNT |
|
Avg Service Time/op(AVG_SERVICE_TIME) |
Average I/O service time for a device (seconds) |
AVG |
utime |
No |
-- |
TOTAL_SERVICE_TIME ÷ TOTAL_IO_OPS |
|
Busy %(BUSY_PERCENT) |
Average percentage of time a disk was busy (%). This value may exceed 100 when processes are continuously executed on a device. |
% |
float |
No |
-- |
((TOTAL_BUSY_TIME ÷ INTERVAL) ÷ DEVICE_COUNT) × 100 |
|
Devices(DEVICE_COUNT) |
Device count |
AVG |
ulong |
No |
-- |
Number of Device Detail (PI_DEVD) records of the category "disk" summarized in the Device Summary (PI_DEVS) record |
|
I/O Mbytes(TOTAL_IO_MBYTES) |
Total size of data transferred through I/O operations (MB) |
AVG |
double |
Yes |
-- |
-- |
|
Interval(INTERVAL) |
Interval at which the Device Summary (PI_DEVS) record was stored (seconds) |
COPY |
ulong |
Yes |
-- |
• When delta values are not checked in real time, RECORD_TIME - last-boot-time • Other cases, RECORD_TIME - previous-record-time |
|
Mbytes Xferd/sec(MBYTES_TRANSFERRED_PER_SECOND) |
Average I/O speed (MB per second) |
R |
float |
Yes |
-- |
TOTAL_IO_MBYTES ÷ INTERVAL |
|
Queue Length(QUEUE_LENGTH) |
Number of I/O requests in the device queue |
AVG |
ulong |
No |
AIX |
sum-of-queue-lengths-of-all-devices ÷ DEVICE_COUNT |
|
Read Ops %(READ_OPS_PERCENT) |
Read operations as a percentage of all I/O operations (%) |
% |
float |
No |
HP-UX, AIX |
TOTAL_READ_OPS ÷ TOTAL_IO_OPS × 100 |
|
Reads(TOTAL_READ_OPS) |
Number of read operations that occurred |
AVG |
ulong |
Yes |
HP-UX, AIX |
-- |
|
Reads/sec(READ_OPS_PER_SECOND) |
Frequency at which read operations occurred (number of read operations per second) |
R |
float |
Yes |
HP-UX, AIX |
TOTAL_READ_OPS ÷ INTERVAL |
|
Record Time(RECORD_TIME) |
Time at which the record was created (Greenwich Mean Time) |
COPY |
time_t |
No |
-- |
-- |
|
Record Type(INPUT_RECORD_TYPE) |
Record type. Always DEVS. |
COPY |
char(8) |
No |
-- |
-- |
|
Seek Ops(SEEK_OPS) |
Number of seek operations |
AVG |
ulong |
Yes |
Solaris, AIX, Linux |
-- |
|
Total Busy Time(TOTAL_BUSY_TIME) |
Total busy time for a device (seconds). This value may exceed the value of Interval × Devices when processes are continuously executed on a device. |
AVG |
utime |
Yes |
-- |
-- |
|
Total I/O Ops(TOTAL_IO_OPS) |
Number of I/O operations that occurred |
AVG |
ulong |
Yes |
-- |
TOTAL_READ_OPS + TOTAL_WRITE_OPS |
|
Total I/O Ops/sec(TOTAL_OPS_PER_SECOND) |
Frequency at which I/O operations occurred (number of operations per second) |
R |
float |
Yes |
-- |
TOTAL_IO_OPS ÷ INTERVAL |
|
Total Service Time(TOTAL_SERVICE_TIME) |
Total service time for a device (seconds). This value includes wait time. In HP-UX, this value indicates the total service time of all I/Os, and therefore, it may significantly exceed the value of Interval × Devices when processes are continuously executed on a device. Even with other OSs, the value may exceed the value of Interval when processes are continuously executed on a device. |
AVG |
utime |
Yes |
-- |
-- |
|
Total Wait Length Time(TOTAL_WAIT_LEN_TIME) |
Total length of time I/Os waited for a device (seconds). The processing capacity of the I/Os that were waiting is divided by the I/Os' processing capacity per second, and is then integrated over the wait time. |
AVG |
utime |
Yes |
AIX |
-- |
|
Total Wait Time(TOTAL_WAIT_TIME) |
Total wait time for a device (seconds). In HP-UX, this value indicates the total wait time of all I/Os, and therefore, it may significantly exceed the value of Interval × Devices when processes are continuously executed on a device. |
AVG |
utime |
Yes |
AIX |
-- |
|
Wait Length Time(WAIT_LEN_TIME) |
Average length of time an I/O waited for a device (seconds). The processing capacity of the I/Os that were waiting is divided by the I/Os' processing capacity per second, is integrated over the wait time, and is then divided by the device count. |
AVG |
utime |
No |
AIX |
TOTAL_WAIT_LEN_TIME ÷ DEVICE_COUNT |
|
Wait Time(WAIT_TIME) |
Average wait time for a device (seconds). In HP-UX, this value indicates the total wait time of all I/Os, and therefore, it may significantly exceed the value of Interval when processes are continuously executed on a device. |
AVG |
utime |
No |
AIX |
TOTAL_WAIT_TIME ÷ DEVICE_COUNT |
|
Write Ops %(WRITE_OPS_PERCENT) |
Write operations as a percentage of all I/O operations (%) |
% |
float |
No |
HP-UX, AIX |
TOTAL_WRITE_OPS ÷ TOTAL_IO_OPS × 100 |
|
Writes(TOTAL_WRITE_OPS) |
Number of write operations that occurred |
AVG |
ulong |
Yes |
HP-UX, AIX |
-- |
|
Writes/sec(WRITE_OPS_PER_SECOND) |
Frequency at which write operations occurred (number of write operations per second) |
R |
float |
Yes |
HP-UX, AIX |
TOTAL_WRITE_OPS ÷ INTERVAL |
- Legend:
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Smry: Summary
Not sprtd in: Not supported in