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Chapter 3: System Administration
iSCSI CRC/Checksum
To enable this option, the initiator can connect with “Data digest” and “Header digest”.
Max Connections
The maximum number of iSCSI connections.
Error Recovery Level
The Error Recovery Level (ERL) is negotiated during a leading iSCSI connection login in traditional
iSCSI (RFC 3720) and iSER (RFC 5046).
ERL=0: Session Recovery
ERL=0 (Session Recovery) is triggered when failures within a command, within a connec-
tion, and/or within TCP occur2 This causes all of the previous connections from the failed
session to be restarted on a new session by sending a iSCSI Login Request with a zero
TSIHRestart all iSCSI connections on any failure2
ERL=1: Digest Failure Recovery
ERL=1, only applies to traditional iSCSI2 For iSCSI/SCTP (which has its own CRC32C)
and both types of iSER (so far), handling header and data checksum recovery can be
disabled2
ERL=2: Connection Recovery
ERL=2, allows for both single and multiple communication path sessions within a iSCSI
Nexus (and hence the SCSI Nexus) to actively perform realligence/retry on iSCSI ITTs
from failed iSCSI connections2 ERL=2 allows iSCSI fabrics to take advantage of recovery
in all regards of transport level fabric failures, and in a completely OS independent
fashion (i2e2 below the host OS storage stack)2
