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7 If configuring bidirectional CHAP, specify incoming CHAP credentials.
Make sure to use different secrets for the outgoing and incoming CHAP.
8 Click OK.
9 Rescan the iSCSI adapter.
If you change the CHAP parameters, they are used for new iSCSI sessions. For existing sessions, new
settings are not used until you log out and login again.
Configuring Advanced Parameters for iSCSI
You might need to configure additional parameters for your iSCSI initiators. For example, some iSCSI
storage systems require ARP (Address Resolution Protocol) redirection to move iSCSI traffic dynamically
from one port to another. In this case, you must activate the ARP redirection on your host.
The following table lists advanced iSCSI parameters that you can configure using the vSphere Client. In
addition, you can use the vSphere CLI commands to configure some of the advanced parameters. For
information, see the Getting Started with vSphere Command-Line Interfaces documentation.
Depending on the type of your adapters, certain parameters might not be available.
Important Do not change the advanced iSCSI settings unless VMware support or Storage Vendors
direct you to change them.
Table 113. Additional Parameters for iSCSI Initiators
Advanced Parameter Description
Header Digest Increases data integrity. When the header digest parameter is enabled, the system performs a
checksum over each header part of the iSCSI Protocol Data Unit (PDU). The system verifies the
data using the CRC32C algorithm.
Data Digest Increases data integrity. When the data digest parameter is enabled, the system performs a
checksum over each PDU data part. The system verifies the data using the CRC32C algorithm.
Note Systems that use the Intel Nehalem processors offload the iSCSI digest calculations for
software iSCSI. This offload helps to reduce the impact on performance.
ErrorRecoveryLevel iSCSI Error Recovery Level (ERL) value that the iSCSI initiator on the host negotiates during a
login.
LoginRetryMax Maximum number of times the ESXi iSCSI initiator attempts to log into a target before ending the
attempts.
MaxOutstandingR2T Defines the R2T (Ready to Transfer) PDUs that can be in transition before an acknowledge PDU
is received.
FirstBurstLength Specifies the maximum amount of unsolicited data an iSCSI initiator can send to the target
during the execution of a single SCSI command, in bytes.
MaxBurstLength Maximum SCSI data payload in a Data-In or a solicited Data-Out iSCSI sequence, in bytes.
MaxRecvDataSegLength Maximum data segment length, in bytes, that can be received in an iSCSI PDU.
MaxCommands Maximum SCSI commands that can be queued on the iSCSI adapter.
vSphere Storage
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