DOCUMENT:Q160000 27-JUL-2001 [sms] TITLE :SMS: Dos4gw.exe Causes Memory Inventory Inaccuracy PRODUCT :Microsoft Systems Management Server PROD/VER:winnt:1.0,1.1 OPER/SYS: KEYWORDS:kb3rdparty kbenv kbinterop kbusage smsgeneral kbArtTypeINF ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft Systems Management Server versions 1.0, 1.1 ------------------------------------------------------------------------------- SYMPTOMS ======== MS-DOS clients that run the DOS extender Dos4gw.exe before Systems Management Server hardware inventory is collected may result in unlikely extended memory values in client inventory. For example, an MS-DOS client with 32 MB of memory that runs Dos4gw.exe in the Autoexec.bat (before hardware inventory is collected) may report 64 MB of extended memory in client inventory. CAUSE ===== Memory inventory is incorrect because Dos4gw.exe is not closing high memory area (HMA) handles it uses to access XMS memory. Dos4gw.exe opens HMA handles to access XMS memory managed by the resident A20 handler (such as Himem.sys). Systems Management Server memory inventory is collected by summing the total amount of memory in use by the available HMA memory handles. In this case, Dos4gw.exe is not closing some HMA handles when it quits, leaving two handles still allocated. In the 32 MB client example Dos4gw.exe opens a handle for 516K, and another for 30,440K. When Dos4gw.exe exits, it does not close its HMA handles; when Systems Management Server inventory sums them with the default handles in use (totaling 31,680K), the extended memory value is reported incorrectly as 62,636K. WORKAROUND ========== To work around this problem, run Dos4gw.exe after the Systems Management Server hardware inventory has been collected. STATUS ====== The products included here are manufactured by vendors independent of Microsoft; we make no warranty, implied or otherwise, regarding these products' performance or reliability. MORE INFORMATION ================ The following table is the combined results of a test application, showing Dos4gw.exe failing to close HMA handles 11 and 12 after closing: Before Dos4gw After Dos4gw Handle 0 = 344 Handle 0 = 344 Handle 1 = 1 Handle 1 = 1 Handle 2 = 8 Handle 2 = 8 Handle 3 = 7 Handle 3 = 7 Handle 4 = 10 Handle 4 = 10 Handle 5 = 5 Handle 5 = 5 Handle 6 = 6 Handle 6 = 6 Handle 7 = 12 Handle 7 = 12 Handle 8 = 6 Handle 8 = 6 Handle 9 = 65 Handle 9 = 65 Handle 10 = 31216 Handle 10 = 31216 Handle 11 = 0 Handle 11 = 516 Handle 12 = 0 Handle 12 = 30440 Handle 13 = 0 Handle 13 = 0 Handle 14 = 0 Handle 14 = 0 Handle 15 = 0 Handle 15 = 0 Handle 16 = 0 Handle 16 = 0 Handle 17 = 0 Handle 17 = 0 Handle 18 = 0 Handle 18 = 0 Handle 19 = 0 Handle 19 = 0 Handle 20 = 0 Handle 20 = 0 Handle 21 = 0 Handle 21 = 0 Handle 22 = 0 Handle 22 = 0 Handle 23 = 0 Handle 23 = 0 Handle 24 = 0 Handle 24 = 0 Handle 25 = 0 Handle 25 = 0 Handle 26 = 0 Handle 26 = 0 Handle 27 = 0 Handle 27 = 0 Handle 28 = 0 Handle 28 = 0 Handle 29 = 0 Handle 29 = 0 Handle 30 = 0 Handle 30 = 0 Handle 31 = 0 Handle 31 = 0 Total = 31680 Total = 62636 Additional query words: ====================================================================== Keywords : kb3rdparty kbenv kbinterop kbusage smsgeneral kbArtTypeINF Technology : kbSMSSearch kbSMS100 kbSMS110 Version : winnt:1.0,1.1 ============================================================================= 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 2001.