Stopping The SAP OS Level Service

How to stop os level service? 
 
This is how you could do it:
 
Starting and Stopping the Gateway Instance 
You check that you can start and stop the Gateway instance by running the startsap and stopsap scripts. 
 
Starting the Gateway Instance 
1. Log on as user <sapsid>adm to the Gateway host.
 
2. Execute the command startsap all G<XX>, where <XX> is the instance number of the Gateway. 
 
Example:
 
If the instance number is 00, then the command is startsap all G00. 
The startup log is written to /home/<sapsid>adm/startsap_GXX.log. 
 
Stopping the Gateway Instance:
 
1. Log on as user <sapsid>adm to the Gateway host. 
2. Execute the command stopsap all G<XX>, where< XX> is the instance number of the Gateway. 
 
Example:
 
If the instance number is 00, then the command is stopsap all G00. 
The shutdown log is written to /home/<sapsid>adm/stopsap_G<XX>.log. 
 
Notes:
If are in UNIX, you can also try:
 
Easy and dirty way : kill PID or kill -9 PID (provided you know which process to be killed) 
 
Hard but clean way : read your stopsap script and profile file, and figure out the command.
 
And
 
Also try: "sapcontrol -nr"