User`s guide

Chapter VII. iSCSI PDU Offload Target
Chelsio T5/T4 Unified Wire For Linux Page 135
Auth_CHAP_ChallengeLength
Auth_CHAP_Policy
The following parameters SHOULD NOT be changed because only one valid value is
supported:
DataPDUInOrder
(support only "Yes")
DataSequenceInOrder
(support only "Yes")
ErrorRecoveryLevel
(support only "0")
OFMarker
(support only "No")
IFMarker
(support only "No")
The following parameters can be changed but would not have any effect because they are
either not supported or they are irrelevant:
DefaultTime2Wait
(not supported)
DefaultTime2Retain
(not supported)
OFMarkInt
(irrelevant because OFMarker=No)
IFMarkInt
(irrelevant because IFMarker=No)
4.11. System Wide Parameters
The Chelsio iSCSI software provides three system wide parameters that can be controlled
through the configuration file, through the use of the command line “iscsictl -G”. The finer
points of these parameters are described in detail here:
4.11.1. iscsi_offload_mode
iscsictl is the tool Chelsio provides for controlling the iSCSI target. It is a Command Line
Interface (CLI) that is invoked from the console. Its usage is as follows:
Options: “AUTO”, “TOE”, or “ULP”, defaults to “AUTO”
TOE: When selected, the iSCSI software attempts to offload the TCP connection. If the
connection can be offloaded, it operates that connection with TCP/IP offloaded in the
Chelsio TOE hardware.
ULP: This is also known as iSCSI Hardware Acceleration. Like TOE mode, when selected
the software attempts to offload the TCP connection. If the connection can be offloaded, it
operates that connection with TCP/IP offloaded in the Chelsio TOE hardware. Additionally
(and differing from TOE mode), it also enables hardware calculations of the header and data
digest and performs Direct Data Placement (DDP) into host memory.
AUTO: When selected the iSCSI software chooses either TOE mode or ULP mode
automatically. It will select ULP mode when the connection is going through a Chelsio iSCSI
acceleration enabled HBA. The purpose of this mode is to optimize the performance of the
Chelsio acceleration hardware.