Quantum Q250 User Manual

There are four different defect lists:
P-list. The primary defect list: the list of defects found when the
drive is tested in the factory. It is written on a system reserved
track and can never be modified by a user--it is preserved for the
life of the drive.
G-list. The grown defect list: the list of accumulated defects
detected during field operation of the drive. The defects are
detected either by the user, or by the read operation.
D-list. The defect data list: the list of defective sectors provided
by the user to request the drive to map them out. The D-list will be
merged into the G-list.
W-list. The working list: the list of defective sectors and their
replacements. The W-list is constructed from the defects combined
from the P-list, G-list, and D-list. This list is used during
operation of the drive.
4.2.4
Updating the Drive Using the Defect Lists
At any time during normal operation, the user can choose to:
o Map out the defective blocks. The user can submit aD-list
of defects, and uses the REASSIGN BLOCKS command.
o Rely on the Automatic Read Reallocation option of the MODE
SELECT command. The drive automatically detects drive
idefects and reallocates the sectors.
o Reformat the drive with the FORMAT UNIT command, using these
combinations of defect lists:
without defect lists
Factory defects only
Grown defects only
Existing defects
Provided defects only
Factory and provided defects
Grown and provided defects
All known defects
(use no defect lists)
(use P-list only)
(use G-list only)
(use P-list and G-list)
(use D-list only)
(use P-list and D-list)
(use G-list and D-list)
(use P-list, G-list, D-list)
In any of the above cases, the drive reconstructs the W-list and
updates the G-list. The P-list, however, remains untouched.
See the Q200 Series Programmers Manual for details on use of the
commands and options mentioned.
4-9

Quantum Q250 Specifications

General

Brand	Quantum
Model	Q250
Category	Storage
Language	English