Dell Emulex Family of Adapters - Manual (Page 980)

Emulex Drivers Version 10.2 for Linux User Manual P010081-01A Rev. A
Appendix F. lpfc Driver BlockGuard Functionality
SCSI Command Support
980
Figure F-2 Data Transfer between Initiator Host and the HBA
The Initiator Operations are listed in Table F-1.
Table F-1 Initiator Operations
Initiator
Operation
Initiator Host <-> HBA HBA <-> Target Comment
NORMAL Unprotected Unprotected Used for unprotected I/O
READ_INSERT Protected Unprotected Reads the data from the target. The
HBA then generates the protection
data and transfers both data and
protection data to the Initiator
host. No protection data is sent on
the SAN. The HBA can insert the
protection data guard tag as CRC or
IP CSUM.
WRITE_STRIP Protected Unprotected Transfers data and protection data
from the Initiator host. The HBA will
verify data integrity, discard
protection data, and only write the
data to the target. No protection
data is sent on the SAN.
READ_STRIP Unprotected Protected Reads data and protection data
from the target. The HBA will verify
data integrity, discard protection
data, and only transfer the data to
the Initiator host. It does not send
the protection data to the Initiator
host. Protection data is only sent on
the SAN.
WRITE_INSERT Unprotected Protected Transfers the data from the Initiator
host. The HBA will then generate
protection data and write both the
data and protection data to the
target. Protection data is only sent
on the SAN.