I have a question. In Oracle Cluster, when Database Instace want to do I/O on a database file stored in ASM it first have to interactive with ASM instance. ASM Instace will provide Database Instance with ASM File Extent Map . ASM File Extent Map will show Database Instance where file's extents . After that Database Instance can perform direct I/O to the Database File. So where is the ASM File Extent Map ?What store ASM File Extent Map ? somebpdy can tell me ???
A complete list in https://twiki.cern.ch/twiki/bin/view/PSSGroup/ASM_Internals
N.A. X$KFFXP extent map table for all ASM files
N.A. X$KFDAT extent list for all ASM disks
N.A. X$KFBH describes the ASM cache (buffer cache of ASM in blocks of 4K (_asm_blksize)
hi, I don't think it reside in ASM Disk header. I have used kfed utility to read ASM Disk Header. There are a lot of information (AU, Disk Group, Voting Disk, ASM SPFile..v..v) but no information about file extent map. Can you explain more about this ? Thanks