How to reset Grace Licensing in Cisco SAN-OS

One of the nice things about SAN-OS (and also NX-OS) is that you can enable features, even if you do not have full licenses installed. What happens is the devices come with a “try before you buy” licensing model where you can try out the features for I believe 120 days. Here is a bit on how this works:

1. This is known as Grace Licensing, think “Grace Period”, and it allows you to use the feature without actually having a license installed.

2. It is limited to 120 days. This means that the countdown starts as soon as the feature is activated. For example, as soon as you enable FCIP, the “SAN Extension” license would start counting down.

3. If you disable a feature, the countdown stops.

4. The countdown only keeps going while the feature is active. So if you power down the device or disable the feature the countdown stops.

What this means is you end up with 120 days of “run time”, not 120 days of “calendar time. This is great news for working in the lab.

One of the issues with buying used equipment, or using lab equipment, is that at some point someone may have used up all the grace licensing. The grace licensing status is stored on the SPROM. And it is possible to actually clear this out. In fact, in earlier versions of SAN-OS doing an “init system” would clear the grace licensing.

“init system” is done at the (boot) prompt. Its very destructive, as it wipes out all code, kickstart, system, and configuration. So no one in their right mind would run this in production, as its very disruptive to do so (every 120 days!). However, Cisco decided to remove this functionality for whatever reason. So if you run out of grace license you are hosed.

Now a 9216a costs maybe $400 (give or take) on ebay. What does licensing cost? Well, if you factor in all the licenses: MAINFRAME, FM SERVER, SAN EXT, ENTERPRISE, etc. Its about $80,000 list. Yes, that’s right, you will pay At least $40,000 or so to turn on all the licensing on your $400 9216a :).

There is a way however. A way for those who have labs. Like most of the information on my site, you can’t get this by searching the Internet, or asking TAC, the truth is most TAC engineers are not actually aware of this.

There is a command “clear license sprom 0” I believe, and that is an interesting command. What is more interesting is actually going into the OS itself, and looking at the scripts/executables which show how the licensing is setup, and how it can be….manipulated. The licensing was in part written by Macrovision (remember those old Cable TV scramblers?). In any case, no need to mess with the shell or sprom. Here is the easy way.

1. Get to the (boot) prompt
2. issue the “init system” command.
3. Once completed reboot
4. You will need to treat this like a MDS with no code, after all you just wiped out everything on it. Download SAN-OS 3.2(1a). Load it onto the MDS.
5. Do the install all procedure to get the kickstart and system images all hooked up and working.
6. Reboot
7. Drop to the (boot) prompt, re-issue “init system”
8. Now reboot and re-install 3.3(5) (or whatever you like)
9. Grace licenses should be reset.

Now I ask that no one do something stupid like try to run this in production. This is for LAB study. This takes time, its not fun to do. However, I will tell you that the average SAN study student will only need to do this at most 1 time. I believe it takes roughly 350-500 hours of on rack time to be fully prepared for the CCIE Storage lab. 120 days of actual runtime is ALOT more than that. So no worries.

If this was helpful please share your comments.

Best of luck!

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