DOCUMENT:Q176170 14-MAR-1999 [exchange] TITLE :XADM: Single Instance Ratio Counter Indicates Value Less Than 1 PRODUCT :Microsoft Exchange PROD/VER:WinNT:4.0,5.0,5.5 OPER/SYS: KEYWORDS:kbusage ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft Exchange Server, versions 4.0, 5.0, 5.5 ------------------------------------------------------------------------------- SYMPTOMS ======== Using Performance Monitor in Microsoft Windows NT, an administrator can monitor the Single Instance Ratio counter for the MSExchangeIS Private and MSExchangeIS Public objects. This value may sometimes show a number between 0 and 1, which can give the impression of a problem with the information store. CAUSE ===== This value represents an approximation of the average instances of every message in the store. Because Microsoft Exchange supports single instances of messages that can be shared by multiple mailboxes, it is possible to have more than one message shared by many users as long as the message remains unaltered and resides in the server store. However, this value may sometimes show a number less than 1 because of the way the algorithm is designed to work and the way messages are internally tracked by the store. A value of less than 1 should be interpreted as close to 1. Additional query words: perfmon ====================================================================== Keywords : kbusage Technology : kbExchangeSearch kbExchange500 kbExchange550 kbExchange400 kbZNotKeyword2 Version : WinNT:4.0,5.0,5.5 Issue type : kbinfo ============================================================================= THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY. Copyright Microsoft Corporation 1999.