symptom;s

1. High disk activity
2. Web site page timeouts;

File
Error	Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding.

1. NT Event Log errors

Source  MSSQLSERVER
Category  Server
Event  1073746968
Computer  VIG1-DB1

Message
Autogrow of file VIGIANT_log' in database 'vigilant' was cancelled by user or timed out after 1312 milliseconds.  Use ALTER DATABASE to set a smaller FILEGROWTH value for this file or to explicitly set a new file size.
Problem; The log is full, or reached a SQL limit or Disk space limit.

Solution;

1. Autorgrowth settings are incorrect, or server is out of space;
2. In database properties, change file autogrowth limits and file growth settings.  Note that a file growth in percent can request a extension that is largers then available disk space for large log files.
3. This problem suggest that the SQL mantenance plan is proably not frequent enough or not working