Chapter 4 SCSI Commands
MODE SENSE (6) / (10) Command (1Ah / 5Ah)
DLT-S4 Interface Reference Guide
201
Data Security Mode Page
(27h)
4
Figure 106
shows the page that controls uses a password verification
mechanism to prevent or allow reading and writing the data to the tape.
Its primary function is to provide a means of preventing unauthorized
access to data on a DLT-S4 native cartridge. It has no impact on Back Read
cartridges.
The password is written to the drive using a
MODE SELECT
command for
the Data Security Mode Page and read from the drive using a
MODE
SENSE
command for the Data Security Mode Page. The password is
written to the tape in response to a
FORMAT
command or
WRITE
command when positioned at the beginning of the tape (
WRITE
from
BOT).
The DLT-S4 drive checks for password protection on the DLT-S4 tape
during the load process and if it is enabled, verifies that the drive has the
same password. If the passwords match, the user can read and write data
on the tape. If they do not match,
READ
and
WRITE
commands will be
rejected and sense data will be presented to the initiator.
Figure 106 Data Security Mode
Page — Data Format
Bit
7
6
5
4
3
2
1
0
Byte
0
PS (0)
0
Page Code (27h)
1
Additional Page Length (32h)
2
Reserved
PAX
PCP
PWF
Reserved
CRA
CWA
3
Reserved
4
Reserved
Password Selection
Scope
5
Reserved
Action Code
6
Reserved
7
Reserved
Number of Passwords Supported
8 — 9
Reserved
APB
APD
PA
TPP
DPS
PM
10
Reserved for Password 2 Status
11
Reserved for Password 3 Status
