Does the Exchange Database Have Sufficient Free Disk Space?

  • Article

Applies To: Exchange Server, Operations Manager 2007

Making sure the disks that host the Exchange databases have sufficient free space is critical to ensuring the availability of messaging services. The Disk Space Monitor targets the Exchange Database Store. It determines the remaining free disk space on logical volumes.

When the disk space is below a specified threshold, the state of the monitor is changed and the following critical alert is raised: "Disk Space Monitor reported a problem." Following are the properties, default thresholds, and the resulting health state for the monitor.

Property Monitored

Default Threshold

Health State

% Free for all drives
  • 2% or less

  • 5% or less
  • Error

  • Warning

MB Free for all drives
  • 400 MB or less

  • 1000 MB or less
  • Error

  • Warning

% Free on Queue drive
  • 5% or less

  • 20% or less
  • Error

  • Warning

MB Free on Queue drive
  • 1000 MB or less

  • 5000 MB or less
  • Error

  • Warning

% Free on Log drive
  • 5% or less

  • 20% or less
  • Error

  • Warning

MB Free on Log drive
  • 1000 MB or less

  • 5000 MB or less
  • Error

  • Warning

Key Rules for Monitoring Exchange Database Free Disk Space

There are over 200 rules to help you monitor the health of the Exchange database. The following table describes the most important rules for monitoring the free disk space.

Rule Name

Alert Properties

Low free disk space

Event-based

Priority: Medium

Severity: Warning

The database engine is rejecting update operations due to low disk space on the designated disk

Event-based

Priority: Medium

Severity: Critical

Very low free disk space

Event-based

Priority: Medium

Severity: Warning

Views for Monitoring Exchange Free Disk Space

The views for monitoring Exchange free disk space, referred to as "storage," are in the Operations Console Monitoring pane in the Microsoft Exchange Server\Exchange 2003\Storage node. The views for monitoring Exchange storage are as follows:

  • Database Performance

  • Database Storage Active Alerts

  • Mailbox Average Messages

  • Mailbox Average size in MB

  • Mailbox Median Messages

  • Mailbox Median size in MB

  • Public Folder Average Message Count

  • Public Folder Median Messages

  • Public Folder Median size in MB

The Database Performance view displays key performance data for the Exchange Database in graphical format. Select the items you want charted, such as Database Table Opens / second, for each managed server running Exchange Server 2003.

The Database Storage Active Alerts view displays alerts generated by the Database Storage monitors and rules. For more information about an alert, see its properties in the Operations Manager 2007 Operations Console.

The remaining views provide performance data, also referred to as "numeric data," about mailboxes and public folders, such as the average size in megabytes (MB).

Reports for Monitoring Exchange Free Disk Space

The reports provided by the Exchange Server 2003 Management Pack are in the Operations Console Reporting pane in Reporting\Exchange Server 2003 (Monitoring). The Exchange Server 2003 Management Pack provides a report titled "Exchange Disk Usage" to help you analyze the Exchange store disk space usage over time.