Seagate ST200FM0002 ユーザーズマニュアル
P
ULSAR
.2 SAS P
RODUCT
M
ANUAL
, R
EV
. C
9
3.8.3
UNMAP
The UNMAP command requests that the device server break the association of a specific Logical Block address from a Physical Block,
thereby freeing up the Physical Block from use and no longer requiring it to contain user data. An unmapped block will respond to a READ
command with data that is determined by the setting of the LBPRZ bit in the READ CAPACITY parameter data.
thereby freeing up the Physical Block from use and no longer requiring it to contain user data. An unmapped block will respond to a READ
command with data that is determined by the setting of the LBPRZ bit in the READ CAPACITY parameter data.
3.8.4
FORMAT UNIT command
A device which supports Thin Provisioning will be capable of performing a SCSI FORMAT UNIT command which allocates Logical Blocks
Addresses that are not linked to Physical Block Locations. A FORMAT command will cause all LBAs to become unmapped.
Addresses that are not linked to Physical Block Locations. A FORMAT command will cause all LBAs to become unmapped.
3.8.5
Protection Information (PI) and Security (SED)
The requirements in this section apply to any device which supports LBA unmapping.
In SCSI devices, umapped LBAs are defined as part of the Thin Provisioning model. Support of the Thin Provisioning model is indicated by
the LBPME bit having a value of '1' in the READ CAPACITY (16) parameter data.
the LBPME bit having a value of '1' in the READ CAPACITY (16) parameter data.
When a region of LBA's are erased via cryptographic erase, as part of the erase, the drive shall unmap those LBAs.
If the host attempts to access an unmapped or trimmed LBA, the drive shall return scrambled data. For a given LBA, the data shall be
identical from access to access, until that LBA is either updated with actual data from the host or that LBA is cryptographically erased. The
drive shall report a value of '0' in the LBPRZ field returned in the READ CAPACITY (16) parameter data.
identical from access to access, until that LBA is either updated with actual data from the host or that LBA is cryptographically erased. The
drive shall report a value of '0' in the LBPRZ field returned in the READ CAPACITY (16) parameter data.
If the host attempts to access an unmapped LBA on a drive that has been formatted with Protection Information (PI), the drive shall return
scrambled PI data for that LBA. Depending on the value of the RDPROTECT field in the data-access command CDB, this may result in the
drive returning a standard PI error to the host.
scrambled PI data for that LBA. Depending on the value of the RDPROTECT field in the data-access command CDB, this may result in the
drive returning a standard PI error to the host.
If the host reduces the addressable capacity of the drive via a MODE SELECT command, the drive shall unmap or trim any LBA within the
inaccessible region of the device.
inaccessible region of the device.
Additionally, an UNMAP command is not permitted on a locked band.
Table 3 PI and SED Drive Configuration
Table 3 PI and SED Drive Configuration
D
RIVE
C
ONFIGURATION
Standard
SED
PI Setting
Disabled
Enabled
Disabled
Enabled
PROT_EN bit
0
1
0
1
LBPME bit
1
1
1
1
LBPRZ bit
1
1
0
0
PI Check Requested
N/A
Yes
No
N/A
Yes
No
DATA Returned for
Thin Provisioned LBA
Thin Provisioned LBA
0x00
0x00
0x00
Random
None
Random
PI Returned for
Thin Provisioned LBA
Thin Provisioned LBA
None
0xFF
0xFF
None
None
Scrambled
PI data
PI data
PI Check Performed
N/A
No
No
N/A
Yes
No
Error reported to Host
No
No
No
No
Yes
No