System management is the task of an individual who is usually referred to, in UNIX literature, as the system administrator. Unfortunately, only a few system administrator activities are straightforward enough to be correctly called administration. This and related guides are intended to help system administrators with their numerous duties.
Topics covered in this chapter are:
This operating system provides its own particular version of system-management support in order to promote ease of use and to improve security and integrity. This chapter presents information on these unique features:
In addition to conventional command line system administration, this operating system provides the following interfaces:
With SMIT, you can:
Web-based System Manager can be configured to run in a variety of operating modes. The operating environments in which it can be started are standalone application, client-server, applet, and remote client. See Web-based System Manager for more information about managing your system with Web-based System Manager.
Following are brief discussions of unique system management features of the operating system.
The Logical Volume Manager (LVM) maintains the hierarchy of logical structures that manage disk storage. Disk drives are defined within this hierarchy as physical volumes. Every physical volume in use belongs to a volume group. Within each volume group, one or more logical volumes of information are defined. Data on logical volumes appears to be contiguous to the user, but can be discontiguous on the physical volume. This allows file systems, paging space, and other logical volumes to be resized or relocated, span multiple physical volumes, and have their contents replicated for greater flexibility and availability.
For more detailed information, see the Logical Volume Storage Overview.
The System Resource Controller (SRC) provides a set of commands and subroutines for creating and controlling subsystems and is designed to minimize the need for human intervention in system processing. It provides a mechanism to control subsystem processes by using a command-line or C interface. This allows you to start, stop, and collect status information on subsystem processes with shell scripts, commands, or user-written programs.
For more detailed information, see the System Resource Controller Overview.
The Object Data Manager (ODM) is a data manager intended for the storage of system data. Many system management functions use the ODM database. Information used in many commands and SMIT functions is stored and maintained as objects with associated characteristics. System data managed by ODM includes:
Certain information about software products and their installable options is maintained in the Software Vital Product Data (SWVPD) database. The SWVPD consists of a set of commands and Object Data Manager (ODM) object classes for the maintenance of software product information. The SWVPD commands are provided for the user to query (lslpp) and verify (lppchk) installed software products. The ODM object classes define the scope and format of the software product information that is maintained.
The installp command uses the ODM to maintain the following information in the SWVPD database:
Workload Manager (WLM) lets you create different classes of service for jobs, as well as specify attributes for those classes. These attributes specify minimum and maximum amounts of CPU, physical memory, and disk I/O throughput to be allocated to a class. WLM then assigns jobs automatically to classes using class assignment rules provided by a system administrator. These assignment rules are based on the values of a set of attributes for a process. Either the system administrator or a privileged user can also manually assign jobs to classes, overriding the automatic assignment. For more information, see Workload Management.
The operating system package is divided into filesets, where each fileset contains a group of logically related customer deliverable files. Each fileset can be individually installed and updated.
Revisions to filesets are tracked using the version, release, maintenance, and fix (VRMF) levels. By convention, each time an AIX fileset update is applied, the fix level is adjusted. Each time an AIX maintenance level is applied, the modification level is adjusted, and the fix level is reset to zero. The initial installation of an AIX version, for example, AIX 5.2, is called a base installation. The operating system provides updates to its features and functionality, which might be packaged as a maintenance level, a program temporary fix (PTF), or a recommended maintenance package.
To determine the maintenance level installed on a particular system, type:
oslevel
To determine which filesets need updating for the system to reach a specific maintenance level (in this example, 4.3.3.0), use the following command:
oslevel -l 4.3.3.0
To determine if a recommended maintenance package is installed (in this example, 5100-02), use the following command:
oslevel -r 5100-02
To determine which filesets need updating for the system to reach the 5100-02 level, use the following command:
oslevel -rl 5100-02
To determine the level of a particular fileset (in this example, bos.mp), use the following command:
lslpp -L bos.mp
The man command is used mainly to access reference information on commands, subroutines, and files. For example, to view information on the ls command, enter:
>man ls
Most of the information displayed is actually taken from formatted HTML files. Many system managers find using the man command more convenient than starting a web browser session when they simply need to find out about a certain flag or the syntax of a given command.
For more information on the man command, see the AIX 5L Version 5.2 Commands Reference. Also see Online Documentation and man Command for BSD 4.3 System Managers.