about srvctl and crs_start command

 since 11g crs is os cluster software used to replace traditional os cluster software.

i alway get some puzzle aboout which command should run in root, which command should run in oracle;

such as srvctl .

1)when i start resource  such as nodeapps. in oracle user we run :

srvctl start nodeapps -n adc1

2)but we try  to remove and add nodeapp , we must in root user run:

srvctl remove/add nodeapps -n adc1 *****

so what the difference with the two below.

the same command with  crsctl ,crs_start,crs_stop .in what situation

command run in root,in what situation command run in oracle;