New 5.1 Distributed Switch Features Part 2 – Configuration Backups and Rollbacks
In Part 2 of this series, I cover two additional features in the newly released vDS 5.1 – Configuration Backup and Restore, along with Rollback and Recovery. All of the technology presented here has been verified and “tinkered with” in the Wahl Network lab on VMware ESXi 5.1.0 build 613838 (beta).
This deep dive series will go into all of the awesome goodies that are baked into the newly released vSphere Distributed Switch (vDS) in version 5.1. I’ve broken the posts up into 4 different parts so that you can sample them at your leisure without having to run through a 40 mile long post. Here are the links to the entire series:
- New 5.1 Distributed Switch Features Part 1 – Network Health Check
- New 5.1 Distributed Switch Features Part 2 – Configuration Backups and Rollbacks
- New 5.1 Distributed Switch Features Part 3 – Port Mirror and NetFlow Enhancements
- New 5.1 Distributed Switch Features Part 4 – LACP, SR-IOV, Elastic Ports, and More
Moving right along …
Configuration Backup and Restore
Prior to the new vDS 5.1, the configuration of the distributed switches was a bit on the volatile side. You had to be careful around them, as often putting them back together required a bit of discovery prior to a change to ensure it could be done. Additionally, there really wasn’t a good, easy way to capture a backup of a working configuration. Enter another really awesome feature in vDS 5.1: the ability to work with vDS configurations on a whole new level.
From an operational standpoint, you now have a lot of new tools at your disposal:
- Backup the vDS / portgroups to disk via an Export operation
- Restore the vDS / portgroups to vSphere via a Restore operation
- Create a new object from backup via an Import operation
- Revert to a previous portgroup configuration after changes are made
Here’s a picture of the new commands in my Wahl Network lab.
Let’s walk through an example …
Backup the vDS
First, let’s take a backup of my WahlNetwork-vDS1 switch. Just right click and start with the “Export Configuration…” option. I’ll go ahead and put a description in to help remember what this backup is for.
As you can see, the option allows you to specify the switch and all port groups, or just the switch itself. If I had performed a backup of the portgroup, the option would not be available. Once the backup completes, you are offered the ability to save the exported file.
Make a Change on the vDS
Now, I’ll remove a portgroup named VLAN254 from the vDS.
And finally, we now see that the portgroup has been removed. I’ve moved the task alert box over so you can see the status is completed.
Restore The Configuration
Now, I simply restore the configuration from backup, and the VLAN254 portgroup is back.
A final prompt will appear to confirm changes and accept.
Not much to it. This feature is really easy to use.
The configuration backup and restore can also be used to grab configurations from one environment and restore them to another. For an organization, this may take shape in the form of having a standard template for deployments at remote sites, or across data centers. I also think this could be valuable to consultants and services groups, as they could build a lab environment out, save the configuration, and then hand it off to a client to be restored and validated.
Rollback and Recovery
One of the strengths of the distributed switch is that changes are rolled out to all of the hosts. This can also work against you if a misconfiguration is introduced on the management vmkernel port groups. If the change would sever the tie from the vCenter server, say from an improper VLAN being configured on the port group, all hosts would lose connection to vCenter. The Rollback feature tries to solve this by working to understand the change prior to commiting it, and then rolling back the configuration change to prevent harm from the environment.
Take this sample image provided by VMware. I’ve pointed out the two connection points where the vmkernel ports hit the distributed port groups. When a change is made that would disconnect the hosts from vCenter, Rollback acts to protect the config and will not commit it.
The improper changes are prevented from occurring thanks to rollback
The Rollback feature can be disabled if so desired.
Additionally, should an issue occur that isn’t solved by Rollback, there is a new Recovery feature that is available directly on the DCUI. The days of having to use a vSwitch to fix a vDS issue on a host are over. The new “Restore vDS” option lets you fix a vDS locally to get connectivity restored, at which time the host then syncs up with the vCenter configuration
A screenshot of the “Restore vDS” option in vSphere 5.1
Once in the Restore vDS screen, you can fix common issues – such as the port being blocked, a teaming policy, or VLAN. I have used this in the home lab and found that it works as advertised.
The Configuration Backup, Rollbacks, and Recovery features are all great new tools in an administrator’s belt for solving problems and preventing issues from occurring. VMware has done a great job at really listening to common concerns from real users, and implemented some very handy methods to overcome them.