ORA Database Error Messages ORA-15026: disk ‘string’ is not an ASM disk September 9, 2015 mpbod ORA-15026: disk 'string' is not an ASM disk Cause: The disk did not contain a valid ASM disk header. Action: Check to see if the data on the disk has been changed by some system administrator action. Back to previous menu Share this:Click to email a link to a friend (Opens in new window)Click to print (Opens in new window)Click to share on Facebook (Opens in new window)Click to share on LinkedIn (Opens in new window)Click to share on Tumblr (Opens in new window)Click to share on Twitter (Opens in new window)Click to share on Pinterest (Opens in new window)Click to share on Reddit (Opens in new window)Click to share on Pocket (Opens in new window)