1.Startup Error:
./cloudera-scm-agent start
Error Screenshot:

2.Delete or backup to other corresponding pid files according to the error report
find/-name cloudera-scm-agent.pid
mv cloudera-scm-agent.pid cloudera-scm-agent.pid20211019
or rm -rf cloudera-scm-agent.pid
3.restart cloudera-scm-agent
./cloudera-scm-agent start
Done!