User Manual

SCSI Commands Reference Manual, Rev. J 159
www.seagate.com Direct Access Block commands (SPC-5 and SBC-4)
P_TYPE (Protection Type) field and PROT_EN bit
The protection type (P_TYPE) field and the PROT_EN bit (see table 124) indicate the logical unit’s current type of protection.
P_I_EXPONENT field
The P_I_EXPONENT field may be used to determine the number of protection information intervals placed within each logical
block (see 3.3.2).
The number of protection information intervals is calculated as follows:
number of protection information intervals = 2
(p_i exponent)
where: p_i exponent is the contents of the P_I EXPONENT field
LOGICAL BLOCKS PER PHYSICAL BLOCKS EXPONENT field
The LOGICAL BLOCKS PER PHYSICAL BLOCKS EXPONENT field is defined in table 125.
Logical Block Provisioning Management Enabled (LBPME) bit
1 If the thin provisioning enabled (TPE) bit is set to one, then the logical unit implements logical block provisioning management (see
SBC-4).
0 If the TPE bit is set to zero, then the logical unit does not implement logical block provisioning management (see SBC-4).
Logical Block Provisioning Read Zeros (LBPRZ) bit
1 If the logical block provisioning read zeros (LBPRZ) bit is set to one, then, for an unmapped LBA specified by a read operation, the device
server shall send user data with all bits set to zero to the data-in buffer.
0 If the TPRZ bit is set to zero, then, for an unmapped LBA specified by a read operation, the device server may send user data with all bits
set to any value to the data-in buffer.
LOWEST ALIGNED LOGICAL BLOCK ADDRESS field
The LOWEST ALIGNED LOGICAL BLOCK ADDRESS field indicates the LBA of the first logical block that is located at the beginning of a physical
block (SBC-4).
Table 124 P_TYPE FIELD and PROT_EN bit
PROT_EN P_TYPE
DESCRIPTION
0 XXXb
The logical unit is formatted to type 0 protection (see SBC-4)
1 000b
The logical unit is formatted to type 1 protection (see SBC-4)
1 001b
The logical unit is formatted to type 2 protection (see SBC-4)
1 010b
The logical unit is formatted to type 3 protection (see SBC-4)
1 011b - 111b
Reserved
Table 125 LOGICAL BLOCKS PER PHYSICAL BLOCKS EXPONENT field
Code Description
0
One or more physical blocks per logical block
[a]
n > 0
2
n
logical blocks per physical block
[a] The number of physical blocks per logical block is not reported.