Understanding WMI Concepts

1. UNDERSTANDING WMI

2. OVERVIEW
• What is WMI?
• Exploring WMI
• Troubleshooting WMI
• WMI Error Codes
• Why do we care

3. WHAT IS WMI?
• History
• Uses
• Components
 Repository
 Namespace
 Class
 Object
 Method

4. HISTORY AND USES
• Introduced and available in Windows Millennium , XP, Vista and later Operating system.
• Was add on Windows 98, 94
• Very handy for script and programming
Ex. Get the installed applications, add users to group, Reboot the computer remotely

5. • SQL server• WMI
COMPONENTS
REPOSITORY

6. NAMESPACE
WMI SQL SERVER

7. CLASSES
WMI SQL SERVER

8. OBJECTS WITH IN CLASSES
WMI SQL SERVER

9. METHOD
WMI SQL SERVER

10. EXPLORING
WMI
• WMI Control , WBEMTest
• File System
• Registry

11. WMI
CONTROL
Can be accessed via
compmgmt.msc
Logged tab disabled in 2008 &
2012

12. WMI
FILE SYSTEM BACKUP AND
REGISTRY SETTINGS

13. WBEMTEST
• This is a tool to access WMI
and view data.
• CIMV2 is root level
namespace
• Create & Delete classes,
run query
• Attached CDROMDrive
Details

14. WBEMTEST
• Local User account details

15. TROUBLESHOOTING
WMI
• Verify error code - 8004xxxxxx
• WMI Logs
• WMIDiag
• Reregister WMI Modules
• Recompile WMI MOFs
• Rebuild WMI – LAST OPTION

16. WMI ERROR CODES
• First, you need to check error codes.
• All WMI Error starts with 0x8004xxx
• Log Location:
• C:WindowsSystem32Wbemlogs

17. WMIDIAG
• It’s a free tool, available in Microsoft
Download Link : https://blogs.technet.microsoft.com/askperf/2015/05/12/wmidiag-
2-2-is-here/
• Looks whether WMI is healthy or not and within WMI like Namespaces are
healthy or corrupted

18. RE-REGISTER WMI MODULES
• Re-register all *.dlls under
Webem directory

19. RECOMPILE WMI
MOFS
• Bunch of Mofs needs to recompiled to
become WMI healthy.
• This command re-compile all Mof files.
• If there is problem with specific
namespace (like SMS,CIMv2)we can
take specific mofs and recompile it.
• MOF files only become effective when
the files are compiled
• Mofcomp.exe used to compile Mof files

20. REBUILD REPOSITORY
• Stop WMI service and rename Repository folder under Wbem folder and start
WMI service.
• It is the last option and it resets the repository fresh.
• Very quick to do that but don’t necessarily fix anything.
• Need to find Root cause and fix the problem.
• Can take backup of WMI and restore it to anyother computer to find what is
going on

21. WHY DO WE CARE?
• Core Dependency for Servers and clients
• SCCM Administrator console
• Engine to access database
• Storage of client data and settings

22. SCCM CLIENT INSTALLATION THROUGH WMI