From Vinod Haval's <Inside Overview of ASM Metadata> These Views helps in understanding the following metrics
  • Physical Mapping
  • Provides Undocumented Information
  • 18 X$ Tables (May be more)
TABLE NAMEDESCRIPTION
X$KFALSThis table gives the details about aliases  created in ASM
X$KFCBHThis is similar to x$kfbh and have same number  of rows as x$kfbh
X$KFCCEThis table helps to locate the particular block
X$KFBHThis table gives more physical block level info
X$KFDSK_STATThis table provides the usage metrics data which can be used for performance analysis
X$KFGRPThis table provides the disk groups info in ASM
X$KFGRP_STATThis table gives the usage metrics data for all the disk groups within the ASM
X$KFGMGThis table provides the details about ASM operations
TABLE NAMEDESCRIPTION
X$KFKIDThis table provides the info about ASM disks
X$KFNCLThis is similar to x$kfbh and have same number  of rows as x$kfbh
X$KFTMTAThis table provides the info about DB instance  connected to ASM instance
X$KFFILThis table gives more physical block level info
X$KFFXPThis table provides the physical extent allocation mapping info within ASM files
X$KFDAT
X$KFDPARTNER
X$KFCLLE