1. Use the ″Erase Disk″ selection to overwrite the data on the drive.2. Do a format without certify.3. Run a second pass of the erase disk selection.For a newly installed drive, you can insure that all blocks on the drive are overwrittenwith your pattern if you use the following procedure:1. Format the drive.2. Check the defect MAP by running the Erase Disk selection.Note: If you use the ″Format and Certify″ option, there may be some blockswhich get placed into the grown defect MAP.3. If there are bad blocks in the defect MAP, record the information presented andensure that this information is kept with the drive. This data is used later whenthe drive is to be overwritten.4. Use the drive as you would normally.5. When the drive is no longer needed and is to be erased, run the same version ofthe Erase Disk selection which was used in step 2.Note: Using the same version of the service aid is only critical if there were anybad blocks found in step 3.6. Compare the bad blocks which were recorded with the drive in step 3 with thosewhich now appear in the grown defect MAP.Note: If there are differences between the saved data and the newly obtaineddata, then all sectors on this drive cannot be overwritten. The new badblocks are not overwritten.7. If the bad block list is the same, continue running the service aid to overwrite thedisk with the chosen pattern(s).This task may be run directly from the AIX command line. The following usagestatement describes the syntax of the command:Usage: diag -c -d -T "format [-s* fmtcert | erase -a {read |write}] [-F]"Flags:fmtcert Formats and certifies the disk.* Available in no-console mode only.-F Force flag. Forces disk erasure even if all blocks cannot be erased due to errorsaccessing grown defect map.Note: Erase option in command line mode uses default values. To selectively read orwrite, use diag in console mode.Chapter 6. Introduction to Tasks and Service Aids 161
