ESX Commands - esxcfg-hwiscsi
Next in the order of commands is esxcfg-hwiscsi. This command according to the iSCSI SAN configuration guide will let you set certain settings as required by your SAN on your hardware iSCSI HBA.
esxcfg-hwiscsi -h - this is the help. Not a ton there but enough.
esxcfg-hwiscsi -l - lists the current settings.
esxcfg-hwiscsi -a - allow arp redirection on the HW iSCSI HBA. This is used be some sans to move traffic between ports.
esxcfg-hwiscsi -j - Will enable a jumbo frame (MTU 9000 bytes) when it is disabled the frame is 1500 bytes.
I will bet if these settings are required you till be directed to use them be the SAN vendor or HBA vendor. IF something bizarre is happening on your iSCSI SAN with hardware HBA’s one of these might not match the SAN.