Equallogic PS4110X Flow Control problem

You are most welcome!

Dwilliam62 THANK YOU!

I disabled DCB and the warning is gone.

Rafko

Hi Don, 

Thanks, The DCB disabling solution works but still the options DCB/VLAN id seems to be applicable to all interfaces as it is group level settings. 

Is there any possibility to disable DCB for selected ethernet interface ?

does this warning is applicable to management interface also ?

Thanks & Regds,

Bala 

DCB is a group wide setting.  So all iSCSI interfaces on all members in that group will no longer use DCB.  It does not apply to dedicated management interfaces, since they don't pass iSCSI traffic

No, the 8024 line lacks two needed ISCSI DCB features, so you need to disable DCB in the EQL GUI.

Don, we get the same message after upgrading EQL firmware from 5.2.5 to 6.0.1, but we're using M8024-k switches - those should be fully DCB compliant or?

Or will that message disappear after correctly configuring DCB on the switch?

Please open a support case, and ask that it be escalated to the Nashua office.  We'd like to gather some more information from the array and switches.

You can see if show recentevents on your EQL returns

1022:41:QRQ:23-Nov-2012 14:20:20.155416:dcb.c:1871:WARNING::9.3.0:Interface eth0 has negotiated DCB priority flow control with the switch. However, the switch did not configure iSCSI traffic for a lossless priority. No Ethernet flow control is enabled for iSCSI on this interface.

To fix it configure flow control manually or change interface to auto-up and allow your storage to configure it.

Setting M8024-k interface to "lldp dcbx port-role auto-up" solved the problem for me.

FYI:  That message will only appear if the array is running 6.0.x firmware and DCB is enabled and negotiated.  Not all 10GbE switches support the specific features iSCSI needs for DCB.   The 8024 is one of the switches that does not yet include the needed features.  You should open a support case to insure that DCB is properly disabled on that switch.

So how could you explain this message:

806:311:EQL6110-1:SP:23-Nov-2012 15:54:12.021766:emm.c:2501:INFO:28.2.131:Ethernet flow control is now enabled on all interfaces.

BTW: I have the newest image (5.0.1.3) installed on the switch.

I've double checked it and it seems to be totally non deterministic. My solution works for one eql storage and doesn't work for another. Both arrays have same firmware revision and are connected to same stacked switches with identically configured ports and only one reports problem.

So probably I'll have to disable DCB which is not the best solution :-/

What the original message is saying is:  "Since I couldn't negotiate the Prioritized Flow Control (PFC) part of DCB,  I can't use it, since DCB is enabled I also can't use 'traditional' link level flowcontrol as a fall back"  

When you changed the LLDP setting that seems to have turned off DCB, which allowed LL Flowcontrol to be negotiated.  Disabling LLDP is one way to disable DCB.

Suggest you open a case with the Power Connect team on the best way to turn off DCB.    The 8100 series fully supports DCB I'm not sure if a future FW release will also do that for the 8000 series switches.

Also specifically on the Dell Power Connect 8024 series you have to first upgrade to the current 5.x firmware to disable DCB.

Thank you so much!!! This helped me a lot. I am seeing the warning many days ago.

Please tell me if i upgrade the eql firmware then, is there any performance issue with I/O reads & writes?