Tachyon HBA Topology setting

[EU-Admins-UNIX]

Hi

Please see our 2 HBAs attached:

According to the forum post below:

http://h30499.www3.hp.com/t5/System-Administration/How-to-change-HBA-Tachyon-settings-parameters/td-p/3298386

the Topology setting is something that cannot be configured.

Our server is connected to our storage over 2 paths.

How are they set?  I have been advised that in our setup we want both to be setup as FABRIC.  What would cause one to be setup as LOOP?  Any idea how one would remedy this?

Regards

Tariq

[Robert_Jewell]

Are you using a switch between the server and storage?

Post the output of  ioscan -fn   The address pathing shown there can also be used to determine the topology.

-Bob

[Matti_Kurkela]

If the HBAs are connected to FibreChannel switch(es), you should check the switch port settings.

Normally, FC switch ports are so-called F_ports, but some switches offer the option of setting ports in loop-capable mode (known as FL_port).

If the switch port for the first HBA is in F_port mode, but the switch port for the second HBA is in FL_port mode, I guess that might cause the indications you're seeing.

If the switch port is in "Auto-sensing", "Fx_port" or "GL_port" mode, these are all various auto-detecting switch port modes than can become (among other things) either F_ports or FL_ports as necessary. That might also confuse the autonegotiation on the HBA side.

Since the HBA port topology cannot be configured, perhaps the SAN administrator can force the switch port to fabric mode? That might allow the HBA to detect the switch port exclusively as a F_port, so the HBA should then select the correct topology.

[EU-Admins-UNIX]

Hi Robert

Yes, we are going via a switch.

Please find attached ioscan -fn.

Regards

Tariq