This article applies to:

• Trustwave MailMarshal (SEG)
• WebMarshal
• 64 bit operating systems are most affected
• Windows Server 2008 R2 is most affected

Symptoms:

• Poor performance
• Slow system response
• High memory usage

Causes:

• Windows system file cache consuming most of the physical RAM

Comments:

As noted by Microsoft, file system cache can consume an excessive amount of physical memory, particularly when many files are being written.

MailMarshal and WebMarshal could encounter this issue because normal operation typically does include writing of many small files (for instance, document unpacking and the WebMarshal Proxy Cache).

The problem is likely to have more impact on 64 bit systems, because the 64 bit architecture permits the system cache working set to be larger than the physical memory.

For more information see:

• Microsoft Knowledge Base article 976618
• MSDN Blog entry: Too Much Cache?

Resolution:

To diagnose this issue you can use the RamMap tool from SysInternals. A large MetaFile entry is an indicator of the issue.

To resolve the issue for most Windows versions you can use the Windows Dynamic Cache service (mentioned in the above Microsoft Knowledge Base article).

• For Windows 2008 R2 and later, you must contact Microsoft to obtain the appropriate tool.

Use of this tool and memory settings are at your discretion.

As a general guideline, on a heavily loaded system you may wish to allow up to 3 GB of memory for use by MailMarshal.