OS tuning roles

Just as we must tune the various components of an Oracle database, we do OS tuning for each of the various server system components. There are several people who play a part in this process.

OS tuning is generally the task of a system administrator (sometimes called an SA), although in some cases the Oracle DBA assumes some of this responsibility. The SA is usually a highly qualified computer scientist (with a BS or MS in Computer Science), who is specially trained to diagnose and remedy environmental issues. There is also a network administrator who configures and monitors network traffic between remote servers.

The tasks of the SA include:

1. Monitoring disk I/O patterns, looking for hot disks and disk bottlenecks
2. Monitoring memory usage, looking for OS paging that indicates a shortage of RAM memory
3. Monitoring CPU usage, looking for cases where tasks are queued waiting for CPU services

A DBA (Database Administrator) can identify cases where tasks are queued waiting for CPU services in Oracle by using various Oracle performance monitoring tools and techniques. Here are some ways a DBA can look for these cases:

1. Oracle Enterprise Manager (OEM): OEM is a graphical user interface (GUI) tool that can be used to monitor the performance of an Oracle database. DBAs can use the Performance page in OEM to identify performance bottlenecks, including cases where tasks are queued waiting for CPU services.
2. Oracle Automatic Workload Repository (AWR): AWR is a built-in repository that stores database performance statistics. DBAs can generate an AWR report to identify performance issues, including cases where tasks are queued waiting for CPU services.
3. Oracle Performance Monitoring (perfmon): perfmon is a command-line utility that can be used to monitor the performance of an Oracle database. DBAs can use perfmon to identify cases where tasks are queued waiting for CPU services.
4. Oracle Dynamic Performance Views (DPV): DPVs are a set of views that provide real-time information about the performance of an Oracle database. DBAs can query the DPVs to identify cases where tasks are queued waiting for CPU services.

In addition to the above methods, a DBA can also use the following techniques to identify cases where tasks are queued waiting for CPU services:

1. Check the operating system performance metrics such as CPU utilization, I/O wait time, and disk queue length.
2. Use Oracle's SQL trace facility to trace SQL statements that are causing high CPU utilization.
3. Use Oracle's session tracing facility to trace individual user sessions to identify queries that are causing high CPU utilization.
4. Monitor the Oracle alert log for messages indicating high CPU utilization or other performance issues.

By using the above monitoring tools and techniques, a DBA can identify cases where tasks are queued waiting for CPU services in Oracle and take appropriate actions to optimize the database performance.

The tasks of the NA include:

1. Monitoring network traffic between routers and servers in a distributed environment
2. Measuring network packets, including packet size and packet speeds between nodes

The roles of the SA and NA are very technical and very challenging. In later modules we will show some of the OS tools used by the SA and NA, and show how Oracle DBAs can use these tools to monitor their external environment.

The next lesson looks more closely at the various external components, starting with an overview of network administration.