22.5.2.1 Database Corruption Basics

No one can guarantee corruption free databases. But you can minimize data loss and operational downtime. Closely monitoring the database and calendar server is key to detecting corruption early. Frequent and complete backups are the key to recovering from corruption once it is found.

There are two levels of corruption possible in a calendar database:

• Application level–Offending entries in one of more database files prevent the server from running when they are operated upon.

• Database level–Corruptions in the Berkeley database pages cause various problems. One common symptom is looping while running csdb check. Another common symptom is an error message like the following:

  “illegal page type or format”, 
  or “page 97895 doesn’t exist, create flag not set.”