debug-services.md

Debug Services

Table of Contents

• The problem
• The solution
• Methodology

The problem

With the scripts built in the Configure Services and Drivers section using service-list-builder, some specific functionality is broken after running the Services-Disable.bat script but works as intended after running the Services-Enable.bat script.

The solution

Determine what services are dependencies of the functionality that is broken, then contribute by posting an issue describing what functionality was fixed so that the services can be added to the config for the future.

Methodology

1. If you haven't disabled services at this stage, run the Services-Disable.bat script

2. Open the Services-Enable.bat script in a text editor

3. Create a new script named Debug-Services.bat

4. Copy the line that sets the HIVE variable (it is set "HIVE=SYSTEM\CurrentControlSet" by default for all systems) and the lines that rename binaries if you have any (these lines begin with REN) to the Debug-Services.bat script

5. If you have any lines that change the LowerFilters and/or UpperFilters registry keys, you will need to handle those first, otherwise, you can continue to step 6. Copy those lines and the line that changes the Start value for each driver in the filter to the Debug-Services.bat script. The null terminator character (\0) is not part of the driver name (e.g. \0iorate is iorate).

   Example

   • An example of what the filters part of the Services-Enable.bat script could look like:

     reg.exe add "HKLM\SYSTEM\CurrentControlSet\Control\Class\{4d36e967-e325-11ce-bfc1-08002be10318}" /v "LowerFilters" /t REG_MULTI_SZ /d "EhStorClass" /f
     reg.exe add "HKLM\SYSTEM\CurrentControlSet\Control\Class\{71a27cdd-812a-11d0-bec7-08002be2092f}" /v "LowerFilters" /t REG_MULTI_SZ /d "fvevol\0iorate\0rdyboost" /f
     ...

   • The lines that must be copied to the Debug-Services.bat script:

     reg.exe add "HKLM\SYSTEM\CurrentControlSet\Control\Class\{4d36e967-e325-11ce-bfc1-08002be10318}" /v "LowerFilters" /t REG_MULTI_SZ /d "EhStorClass" /f
     reg.exe add "HKLM\SYSTEM\CurrentControlSet\Control\Class\{71a27cdd-812a-11d0-bec7-08002be2092f}" /v "LowerFilters" /t REG_MULTI_SZ /d "fvevol\0iorate\0rdyboost" /f
     reg.exe add "HKLM\SYSTEM\CurrentControlSet\Services\EhStorClass" /v "Start" /t REG_DWORD /d "0" /f
     reg.exe add "HKLM\SYSTEM\CurrentControlSet\Services\fvevol" /v "Start" /t REG_DWORD /d "0" /f
     reg.exe add "HKLM\SYSTEM\CurrentControlSet\Services\iorate" /v "Start" /t REG_DWORD /d "0" /f
     reg.exe add "HKLM\SYSTEM\CurrentControlSet\Services\rdyboost" /v "Start" /t REG_DWORD /d "0" /f

6. Copy the lines that enable the next 10 services from the Services-Enable.bat script to the Debug-Services.bat script

7. Run the Debug-Services.bat script with NSudo and restart your PC

8. Test the functionality. If it is NOT working then return to step 6, otherwise, continue to step 9

9. Disable the last 10 services in the Debug-Services.bat individually by changing the start value to 4 then restart your PC. You will need to check whether it is even possible to disable each service by checking whether it is not 4 in Services-Disable.bat. If it is 4, then you can safely disable it however, if it is not 4, do not disable the service under any circumstances, otherwise you may BSOD. Keep repeating until the functionality breaks again. It is recommended to delete the lines for services that you can not disable

10. Now that you have identified which service breaks the functionality, try to re-enable it. If you can reproduce the functionality breaking while the service is disabled and works with it enabled, make a note of this service and continue to the next step

11. Delete Debug-Services.bat as it is no longer required

12. The service's dependencies must also be enabled if there are any. service-list-builder can be used to get the entire dependency tree for a given service with the command below

    service-list-builder.exe --get_dependency <service> --kernel_mode

13. Get the default start value for each service that you noted down from the Services-Enable.bat script, then edit the start value in the Services-Disable.bat script for the corresponding service. Run the Services-Disable.bat script with NSudo to check whether the functionality is working. If it is not working, return to step 1 and repeat the entire process with the newly edited/latest Services-Disable.bat script. This is because a service that is required for the functionality might not have any service dependencies

14. Report all the services that you noted down by posting an issue describing what functionality was fixed by enabling the noted services