Table 15: Product Configuration and Bit Settings
Bit
Product Configuration
Bit Settings Description
SED
Support
Non-SED
Support
LBPME Y Y LBPME = 1 (Logical unit is thin
provisioned)
LBPM is implemented.
LBPME = 0 (Logical unit is fully
provisioned)
LBPM is not implemented.
LBPRZ N Y LBPRZ = 1 For an unmapped LBA specified by a READ opera-
tion, the device server sends to the data-in buffer
user data with all bits set to 0.
LBPRZ = 0 For an unmapped LBA specified by a READ opera-
tion, the device server sends to the data-in buffer
user data with all bits set to any value.
UNMAP Command
The UNMAP command requests that the device server break the association of a specif-
ic LBA from a physical block, thereby freeing up the physical block from use and no lon-
ger requiring it to contain user data. An unmapped block will respond to a READ com-
mand with data that is determined by the setting of the LBPRZ bit in the read capacity
parameter data.
Protection Information (PI) and Security (SED)
Requirements in this section apply to any device that supports LBA unmapping. In a
SCSI device, an umapped LBA is defined as part of the thin provisioning model, whose
support is indicated by an LBPME bit value of 1 in the read capacity parameter data.
When a cryptographic ERASE command erases a region of LBAs, the drive unmaps
those LBAs. And when the host attempts to access an unmapped or trimmed LBA, the
drive returns scrambled data.
For a given LBA, data is identical from access to access until it is either updated from
the host or is cryptographically erased. Then the drive reports an LBPRZ bit value of 0 in
the read capacity parameter data
When the host attempts access to an unmapped LBA on a drive that has been formatted
with protection information (PI), the drive returns scrambled PI data for that LBA.
Depending on the value of the RDPROTECT field in the data-access command CDB, the
drive might return a standard PI error to the host. When a host reduces a drive's ad-
dressable capacity via a MODE SELECT command, the drive unmaps or trims any LBA
within the inaccessible region of the device. Additionally, an UNMAP command is not
permitted on a locked band. PI and SED drive configuration information is shown be-
low.
Preliminary
S600DC Series 1.8-Inch SAS NAND Flash SSD
SAS Features
PDF: 09005aef86470b9b
s600dc_series_1_8_sas_ssd.pdf - Rev. F 3/16 EN
11
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