DB2 Performance Expert for Multiplatforms V2.2, 2nd Edition

540 DB2 Performance Expert for Multiplatforms V2.2

Operating system monitoring

In addition to a large variety of DB2 metrics, PE also keeps track and displays

OS-level metrics. There are two links in the PE System Overview window to view

OS-level data.

Operating System Information links to the rather static data, such

as configured memory, installed CPUs, and file system information.

Operating

System Status

links to more volatile metrics about paging, processes, CPU

consumption, and disk utilization (Figure C-18). All OS-level data is enabled for

history monitoring.

Figure C-18 Operating System monitoring

File system usage

As your BI system grows over time, you typically want to verify that the storage

resources are still sufficient. You might also want to keep an eye on storage that

is needed only temporarily. This is important because BI systems tend to perform

large sorts that might require some dedicated disk space. The OS Information

window provides an overview of storage resources (Figure C-19 on page 541).

Appendix C. DB2 Performance Expert For Business Intelligence 541

Figure C-19 File system usage

542 DB2 Performance Expert for Multiplatforms V2.2

Disk I/O

Click the Disk Utilization (Delta) category of the OS Status window to display

disk I/O metrics (Figure C-20). This window shows the transferred (that is, read

and written) kilobytes and total number of I/O operations. Note that this data is

based on delta intervals. You can either manually refresh the window or see this

data based on the time between the recent two refreshes, or you can use the

auto-refresh option.

Figure C-20 Disk I/O

CPU utilization, queues, and paging

The OS Status window also contains information about CPU and paging in the

Performance category (Figure C-21 on page 543).

The Run Queue Length field indicates how many processes are actually ready

for execution, and the Block Queue Length field shows the number of processes

that are waiting for I/O to finish.

Paging is counted in the number of pages being paged in or paged out.

Appendix C. DB2 Performance Expert For Business Intelligence 543

The CPU utilization is divided into user time, system time, I/O wait time, and idle

time.

Both CPU utilization and paging data is based on delta values. You can either

click the Refresh button to see the data based on the time between previous and

current refresh, or you can use the auto-refresh feature.

The paging rate and block queue length data can also be visualized in the

System Health pane, and they can be used for threshold definitions for

exceptions.

Figure C-21 CPU utilization