Wmitrace - strange behavior

WINDBG
1

After struggling for 2 days (not continuously) to get WMI tracing in
Windbg working in my driver and only getting output like: (Traceview on
the target was working fine.)

Unknown( 14): GUID=6a1d2a50-0b77-e721-383a-1185eb765960 (No Format
Information found).
Unknown( 10): GUID=c352d428-a6f7-c208-41a6-c0acc8d30dfb (No Format
Information found).

I discovered, quite by accident, that the trace format search path set by
either the env var TRACE_FORMAT_SEARCH_PATH or the !wmitrace.searchpath
had better not contain an underscore (‘_’) character!

Another minor irritant is the fact the the ‘guidfile’ path is reset when
the target is restarted and I have to re-enter it.

Also - Does anyone know how to enable WMI tracing at system startup in
Windbg? Having to logon and issue a tracelog command doesn’t always do it
for me.

Grrr…. /ted

2

Correction: After some more testing, it was determined the
!wmitrace.searchpath command doesn’t seem to work at all. I merely
confused myself by switching to an env var and changing the target path at
the same time.

However, my other observations/comments are still valid. Sorry for any
confusion.

/ted