Which tool or utility can provide you details about what SCANDISKS is doing?

You find that oracleasm scandisks command is not discovering all your ASM disks. Which tool or utility can provide you details about what SCANDISKS is doing?

A.
strace utility

B.
OS Watcher (OSW)

C.
System Activity Reporter (sar)

D.
Remote Diagnostics Agent (RDA)