Data Integrity Validation - Oracle StorageTek T10000 Reference Manual

This appendix contains information about the Data Integrity Validation (DIV) feature
for the T10000 tape drive. This feature is based on the ANSI T10 Technical
Committee's implementation of the Data Integrity Field (DIF).
The terms DIV or DIF are also referred to as Protection Information (PI).

Data Integrity Validation

Oracle's StorageTek T10000-Series tape drive supports the Data Integrity Validation
(DIV) feature. This feature provides end-to-end protection of user data during a
transfer.
Initiators generate the Protection Information (PI) during a write operation.
Any object associated with the I_T_L nexus
bus adapter; Target: controller or device) may check for this information.
Once the device receives the protection information (for example, written to tape), it
keeps this information until overwritten. Any loss of power, hard reset, or a logical
unit reset has no effect on the retention of this protection information.
Protection information is appended to the end of the record using the following
format for the PI data.
• The Logical Block field contains the original user data.
• The Protection Information field contains the CRC.
Note –
1. The capability of the drive to support DIV is advertised in Inquiry data and Mode
Sense data.
2. To enable or disable DIV protection mode—use the Mode Select command.
3. Once enabling DIV mode; only the following commands are affected:
1. I_T_L nexus: A nexus is a connection that exists between an initiator, a target, and a logical unit.
This is where one Initiator Port talks to one Target Port, addressing one LUN and together they
execute one Task.
August 2016
Data Integrity Validation
Logical Block Protection Information (4-byte CRC)
1
(such as the Host: application or host
Data Integrity Validation 243
A