To protect the communciations between an iSCSI initiator and target, the iSCSI protocol allows an enhanced CRC32 checksum to be used (this isn’t enabled on most initiators and targets by default) to protect the iSCSI headers and data payload. The Solaris iSCSI initiator supports both header and data payload checksums, which can be enabled with the iscsiadm utility:
$ iscsiadm modify target-param –headerdigest CRC32 target1
$ iscsiadm modify target-param –datadigest CRC32 target1
I have been doing some testing to see how much overhead and latency this places on the iSCSI communication process, and will make sure to blog my findings once my research is complete.