ASM keeps metadata in the first allocation units of the disks (first two typically) and also has metadata files (regular ASM files with file number < 256 so that you would not see them in v$asm_file). Some info on what metadata files are available is in https://twiki.cern.ch/twiki/bin/view/PSSGroup/ASM_Internals, more details in the book Oracle Automatic Storage Management, Osborne Oracle Press 2007, N. Vengurlekar, M. Vallath and R. Long. Regards, Luca -----Original Message----- From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx] On Behalf Of hrishy Sent: Thursday, February 26, 2009 6:45 AM To: knecht.stefan@xxxxxxxxx; Niall Litchfield; dannorris@xxxxxxxxxxxxx Cc: oracle-l@xxxxxxxxxxxxx Subject: Re: ASM tracking datafiles Hi Dan/Niall Thanks for providing the detailed answer i was looking for. I have one more question though since ASM does not have a control file where does it keep the information of all the disks and diskgroups Luca Thanks for the valuable link its simply amazing to see the level of details on ASM on your site very handy for troubleshooting regards Hrishy -- //www.freelists.org/webpage/oracle-l -- //www.freelists.org/webpage/oracle-l