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HBA 8gb with 4gb san switch

Trusted Contributor

HBA 8gb with 4gb san switch


i want to connect one HBA to a dl380 g7 server runnung linux redhat enterprise 5.4 64BIT.
my problem is, the switch is 4GB and the card is 8GB. how to force the server to use only 4gb speed to be able to communicate with the switch?

systool -vc fc_host
Class = "fc_host"

Class Device = "host2"
Class Device path = "/sys/class/fc_host/host2"
fabric_name = "0x5001438009ac9c23"
issue_lip =
node_name = "0x5001438009ac9c23"
port_id = "0x000000"
port_name = "0x5001438009ac9c22"
port_state = "Online"
port_type = "Unknown"
speed = "unknown"
supported_classes = "Class 3"
supported_speeds = "1 Gbit, 2 Gbit, 4 Gbit, 8 Gbit"
symbolic_name = "HPAK344A FW:v4.04.09 DVR:v8."
system_hostname = ""
tgtid_bind_type = "wwpn (World Wide Port Name)"
uevent =

Device = "host2"
Device path = "/sys/devices/pci0000:00/0000:00:08.0/0000:0b:00.0/host2"
ct =
edc =
els =
fw_dump =
nvram = "ISP "
optrom_ctl =
optrom =
reset =
sfp =
uevent =
vpd = "&"


please help!
Honored Contributor

Re: HBA 8gb with 4gb san switch

The HBA should automatically detect that the switch is not capable of operating with the 8GB speed and adjust to 4 GB. Normally you don't have to do anything.

FibreChannel speed detection is much simpler and more robust than NIC autonegotiation: I've never had any speed detection problems with FibreChannel HBAs.

Honored Contributor

Re: HBA 8gb with 4gb san switch

Well.. if you already cabled your 8Gbit FC HBA to your 4Gbit Switch port and there is no connection and your HBA is still showing 8Gbit speed -- then make sure your switch port is set to auto-speed sensing instead of forced 4Gbit only.

Or better yet, set your switch port to 4Gbit and set your HBA as well to explicit 4Gbit.
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Trusted Contributor

Re: HBA 8gb with 4gb san switch