The BADLIST command displays a per-AMP list of cylinders whose contents cannot be determined.
Cylinders are designated as bad automatically when a data corruption in the cylinder index prevents the system from determining the contents of the cylinder. A list of bad cylinders is maintained on each AMP. AMPs that own bad cylinders are kept down, and the file system is not started on these AMPs during Teradata Database system startup. To bring the AMPs back up, use Filer to repair or reinitialize the bad cylinders.
The BADLIST command can scan these cylinders for possible diagnoses. After the bad cylinders have been fixed, use the ASSIGN command to reassign the cylinders to an AMP and storage type, or use the /R option of BADLIST to remove the cylinder from the list, making the cylinder available for use from the general pool of storage cylinders.
For more information on the ASSIGN command, see ASSIGN.
- The 64-bit identifier of a cylinder, entered as a 16-character hexadecimal number.
- Prints the list of bad cylinders. This is the default.
- Scans a bad cylinder and attempts to diagnose problem. If no cylid is specified, scans all bad cylinders.
- Initializes a bad cylinder and releases it back into the general storage pool. If no cylid is specified, initializes and releases all bad cylinders.
- /X cylid
- Initializes the cylinder specified by cylid, but does not release it back to storage. Used for durable cylinders, which should never be released to general storage, such as those used for master indexes and startup information.
BADLIST can be used only when the Teradata Database is down.
The /R option is related to the ASSIGN command. The /R option releases a repaired cylinder back into the general storage pool, while ASSIGN re-associates a repaired cylinder back to a specific AMP.
For more information on the proper use of this command to repair large file system structures, see Repairing Cylinders