

Overview

SWVR Lifeguard is a system service that watches the Storage Pools used 
by Microsoft Exchange 5.5.

If you install Microsoft Exchange on a Virtual Disk, SWVR Lifeguard will 
monitor the free space in the storage pool that contains the virtual disk,
and will shut down Microsoft Exchange in an orderly fashion when a free
space threshold is reached.

By default, when the storage pool has only 10MB left, SWVR Lifeguard will 
shut down Microsoft Exchange.  This check is made once every 2 minutes and 
has very little performance impact upon your system.  These defaults can be 
changed by creating and/or modifying settings in the system registry.



Installation

To install SWVR Lifeguard, copy SWVRMON.EXE to a directory on your local hard 
disk, preferably your system disk.  Type "SWVRMON /service" to configure the 
service on the system.  If the system is a member of a Microsoft Cluster, perform
this operation on all members of the cluster.

To start SWVR Lifeguard, use the Control Panel / Services icon to start 
the service, or type "NET START SWVRMON" from a command prompt.

On a Microsoft Cluster Server, do not start the service locally.  Using the 
Cluster Administrator, create a new "Generic Service" resource in the group 
that contains Microsoft Exchange and the "SCE Pool" resource that represents 
the storage pool.  This service can then be brought online to monitor the 
storage pool.  When using the Create Resource Wizard, provide the value 
"System\CurrentControlSet\Services\SWVRMON\Parameters" on the registry
key replication page.



Normal Operation

SWVR Lifeguard will determine which disks are being used by Microsoft Exchange 
to store data.  Each disk is then checked to see if it is a virtual disk.  If it is
a virtual disk, the storage pool that the disk is from is checked for its amount
of current free space.  If the amount of free space is less than a specific threshold 
(10MB by default), Microsoft Exchange is gracefully shut down.

SWVR Lifeguard will post events in the Application Event log and can be viewed
using the Event Viewer.  An event will be entered for each disk that exceeds the 
threshold, and then events when the shutdown of Microsoft Exchange has started 
and completed.  If there are any errors in shutting down any of the various 
services used by Microsoft Exchange, an error event will be posted as well.  Between the start shutdown and completed shutdown events, various Microsoft Exchange services may post events in the Application and System Event Logs to detail the results of their shutdown.

On a Microsoft Cluster Server, the cluster resources for Microsoft Exchange will be taken off-line.  For non-cluster configurations, the local services that makes up Microsoft Exchange will be stopped.



Post-shutdown

Once SWVR Lifeguard has shutdown Microsoft Exchange, a system administrator can 
observe the event log to see which disks used by Microsoft Exchange are currently
in storage pools that are too full.  Using the SWVR management tools, the system 
administrator can free up space in the pool by adding disks to the storage pool 
or deleting other virtual disks or snapshots.

After providing more free space in the storage pool, Microsoft Exchange can be restarted.



Advanced Configuration

By default, SWVR Lifeguard will check the state of disks and storage pools every two 
minutes, and will shut down Microsoft Exchange if there is 10MB or less in a storage pool
being used by Microsoft Exchange.

To change these values, use the Registry Editor (REGEDT32 or REGEDIT) and add and/or modify 
the following values:

Registry key:	HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\SWVRMON\Parameters
Value:			CheckEveryMinutes			REG_DWORD	Number of minutes between space 
														checks ( >= 1 minute)
				FreePoolSpaceThresholdMB	REG_DWORD	Amount of free space left in pool 
														in MB (>= 0 MB)

