OpenVMS Integrity Monitoring

Many problems that occur within a system are not preventable, such as, disks that run out of space, hardware failures, and stalled print queues. These problems do not just happen spontaneously but they develop over time. Through vigilant monitoring of system integrity, one can often detect a developing problem before it becomes critical. This chapter discusses system events that are clues to pending problems. A number of DCL command procedures that provide automatic problem detection and reporting are also discussed. Whenever hardware errors occur, the OpenVMS error formatter (ERRFMT), a detached process, writes an error record to the system error log file. The error log file contains a record of all system and device errors that occurred since the log file was created. ERRFMT does not send a notification message when device errors occur. Therefore, a user must monitor hardware errors using utilities. Even when disk space is carefully managed, disks run out of space. This can occur if a user accidentally creates a large file or when a software problem creates a large log file. Running out of disk space has a severe effect on users. Users trying to save documents might lose their work, or other key system tasks might fail in the middle of a large process, leaving files or databases in corrupted states. To prevent these problems, a user should periodically monitor disk space using the SHOW DEVICE command.