How do I find all the ETW sessions on the machine?

logman is your tool for this. Here is how you can query for all the sessions and also how to see values from a particular session.

 c:\> logman -ets

Data Collector Set                      Type                          Status
-------------------------------------------------------------------------------
AITEventLog                             Trace                         Running
Audio                                   Trace                         Running
DiagLog                                 Trace                         Running
EventLog-Application                    Trace                         Running
EventLog-System                         Trace                         Running
NtfsLog                                 Trace                         Running
SQMLogger                               Trace                         Running
UBPM                                    Trace                         Running
WdiContextLog                           Trace                         Running
MpWppTracing                            Trace                         Running
FSysAgentTrace                          Trace                         Running
MSMQ                                    Trace                         Running
MSDTC_TRACE_SESSION                     Trace                         Running
test_trace                              Trace                         Running

The command completed successfully.


c:\> logman test_trace -ets

Name:                 test_trace
Status:               Running
Root Path:            C:\
Segment:              Off
Schedules:            On
Segment Max Size:     500 MB

Name:                 test_trace\test_trace
Type:                 Trace
Output Location:      C:\09_19_44.etl
Append:               Off
Circular:             On
Overwrite:            Off
Buffer Size:          8
Buffers Lost:         0
Buffers Written:      1
Buffer Flush Timer:   0
Clock Type:           Performance
File Mode:            File

Provider:
Name:                 Microsoft-Windows-Application Server-Applications
Provider Guid:        {C651F5F6-1C0D-492E-8AE1-B4EFD7C9D503}
Level:                5
KeywordsAll:          0x0
KeywordsAny:          0xffffffff
Properties:           0
Filter Type:          0

The command completed successfully.