Archive for June, 2014

Cisco Nexus 1000v: VEM needs an VMK interface to connect to VSM

June 26th, 2014 Comments off

A VMK (VM Kernel) interface is a virtual interface that ESXi itself uses to connect to the outside world. When we first setup an ESXi, VMK0 is setup to be the management interface.

When you install Nexus 1000v, the VEM modules need a way to communicate to the VSM modules, and we need a VMK interface on the ESXi hosts to do this.

If you choose to use the management VMK interface (normally VMK0) for layer 3 control, that VMK will need to be moved over to the Nexus 1000V, where it will sit ‘behind’ the VEM or else VSM will not ‘see’ the VEM (i.e. it won’t appear in the output of ‘sh mod’) until the VMK interface is moved to the VEM.


For myself I prefer to have VMK0 interface “out of band”. I leave VMK0 with vSwitch0 and create a new VMK1 interface for the VEM communication


If you choose this option, you may need to configure static routes on the ESXi host if the two VMK interfaces are in different VLANs – for example, a default gateway would be configured via VMK0, while a more specific static route would be configured via VMK1 towards the VSM IP address.

EMC VNX – Updating firmware has crashed. Now what?

June 12th, 2014 Comments off

Today I downloaded the newest firmware update for a pair of VNX 5400. The first update went well. I then started to update the 2nd one. The process took about 2 hours for the first one. I didn’t want to wait so I left it there uploading. About 3 hours later, I went back and this had happened

java crashed

Now what ?

I started to check the VNX, logging in appeared to be fine. The software shows the correct latest version. I performed a few operations , created, deleted a few LUN, everything seemed fine. Should I leave it as that ? Do I want to call EMC and stay on the phone for 2 hours for EMC support helpdesk to check it ?

Luckily, I found out that USM does show the status of the last update. It also shows the time the Update started and the time it took to finish. Everything seems to be perfect.

Note that you can also run a “Health Check”. Click the picture for more details.


Categories: Data Center, Storage