DOCUMENT:Q178658  21-MAR-1999  [exchange]
TITLE   :XADM: KCC Uses Increasingly Large Amounts of Memory
PRODUCT :Microsoft Exchange
PROD/VER:WinNT:5.0
OPER/SYS:
KEYWORDS:

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The information in this article applies to:

 - Microsoft Exchange Server, version 5.0 
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SYMPTOMS
========

As the number of sites in an organization grows, the knowledge consistency
checker (KCC) consumes more and more memory each time it runs. With 212+
servers, the directory service has been observed to use 110 MB of virtual memory
routinely, and at peak has grown to the point where all virtual memory in the
system is used, causing out-of- memory failures in the directory service and
other services. Whenever the KCC runs in such cases, Windows NT and Exchange
become almost entirely unresponsive and replication slows drastically.

The Exchange Administrator program may also crash with a memory violation when
you try to select the global address list on a server that contains a great
number of sites.

CAUSE
=====

The Exchange database uses 4-KB pages and sets up the maximum record size to be
3,784 bytes each. The directory stores the information for the sites in one
object, each taking about 12-20 bytes of space. When the record size is too
large, the directory accepts the additional information and does not record any
problems.

STATUS
======

Microsoft has confirmed this to be a problem in Microsoft Exchange Server
version 5.0.

This problem has been corrected in the latest U.S. Service Pack for Microsoft
Exchange Server version 5.0. For information on obtaining the Service Pack,
query on the following word in the Microsoft Knowledge Base (without the
spaces):

   S E R V P A C K


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Keywords          :  
Technology        : kbExchangeSearch kbExchange500 kbZNotKeyword2
Version           : WinNT:5.0
Issue type        : kbbug
Solution Type     : kbfix

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