Celerra / VNX File / VG Gateway and adjusting the lacp hello timers

**Please be aware that following the steps below will require you to reboot your datamover and will disrupt traffic!!

Ok you are minding your own business and the networking guy calls you in the middle of the night during the change window and starts panicking, they had an update scheduled, it was supposed to be non-disruptive, but they are saying the ports to your datamover are causing it to not be disruptive they are sending you stuff you have never seen before:

cisco-nexus7k-01# show lacp issu-impact
For ISSU to Proceed, Check the following:
1. All port-channel member port should be in a steady state.
2. LACP rate fast should not be enabled on member ports.

The following ports are not ISSU ready
Eth6/13 , Eth4/14 , Eth5/14 , Eth6/14 , Eth4/23 ,
Eth4/24 , Eth3/13 , Eth4/13 , Eth5/13 , Eth3/14 ,

Funny a few of those ports are your datamovers LACP ports..

So what can you do to help the networking team not have a disruptive update of their expensive cisco switch?

You start digging around you pull up the “command reference for file” pdf and heck all you can see is how to adjust the failover type for the LACP trunk you have.
server_sysconfig

[protocol=lacp]
Initializes link aggregation control protocol for Ethernet devices
that allows a non-exponential number of devices. For example,
one, three, or five entries.

[lb=mac|ip|tcp]
Specifies the statistical load balancing method that applies to the
aggregator/trunk. The mac option indicates that the output link
on the trunk/aggregator is chosen based on source and
destination MAC addresses. The ip (default) option indicates that
the output link on the trunk/aggregator is chosen based on
source and destination IP addresses. This is useful in the situation
that the Data Mover is connected to a router or to a layer 3 switch.
The tcp option indicates that the output link on the
trunk/aggregator is chosen based on source and destination IP
addresses as well as source and destination TCP ports.

Great that has nothing to do with some silly hello timer or whatever they are calling it (and why would that cause their supper expensive switch to not do a non-disruptive update? (we will leave those issues to networking guys)).

Ah ha there is another document you need to reference the Parameters guide.. in there you find exactly what you need you can fix the issue and send the network guys on their way and get some sleep:

server_param server_2 -f lacp -i timeout -v

But the command fails:

server_2 :
Error 2111: server_2 : Unsupported argument: lacp

Fear not, there is a “Documentation Bug” and as per emc305565

Here is how you can update the setting and make your changes:

.server_config server_2 -v “param” |grep -i lacp

Name      Location      Current      Default
—-      ———-      ———-      ———-
lacp.timeout 0x0003f88840 ‘short’ ‘short’

To modify this parameter follow these steps:

1. Log in as nasadmin and su to root.

2. Edit file /nas/server/slot_2/param.

3. Add this entry to the file and save:

param lacp timeout=long

4. Reboot the Data Mover:

(This will disrupt traffic!!! and reboot your datamover) /nas/bin/server_cpu server_x -m -reboot now (This will disrupt traffic!!! and reboot your datamover)

After it comes back up you should be able to run:

.server_config server_2 -v “param” |grep -i lacp

and now see

Name Location Current Default
—- ———- ———- ———-
lacp.timeout 0x0003f88840 ‘long’ ‘short’

I hope some one out there finds this helpful, as when I was presented with this issue I was going ??what are you talking about..!

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This entry was posted in EMC, Storage Arrays, VNX File. Bookmark the permalink.

2 Responses to Celerra / VNX File / VG Gateway and adjusting the lacp hello timers

  1. Dave says:

    Cool- Our Nexus admin just ran this by me today and I had the same response, until I found this link. Thanks!

  2. Curtis Smith says:

    Fantastic post. We ran into this last night. Thanks for the info!

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