Where am I? It’s dark and I’ve lost my network settings! How innocuous editing of NetApp config file can lead to lost IPs

So I was performing an initial configuration of a FAS3270 the other day when I changed the interface group information via PuTTY. Specifically, I deleted and recreated the interface groups manually instead of running setup. After I did this and following a reboot of the filer, the IP addresses for both interface groups were missing. Performing an ‘ifconfig -a’ before the reboot, I saw the IP addresses assigned correctly:

And after the reboot, this is what I saw:

What happened to the IP addresses? The /etc/rc file appeared correct:

And the /etc/hosts file had the correct entries:

Once rebooted, the filer should replace the ‘hostname’ string in the /etc/rc file with the IP address referenced in the /etc/hosts file. All looks good. It turns out another engineer I was working with, Chris H., had run across this problem before. Again, I edited this particular filer manually with ‘ifgrp’ and ‘ifconfig’ rather than running setup and letting the filer edit the relevant text files itself. As so many folks do, I was running a console session from a Windows laptop and copying, editing, and pasting the lines to and from Windows Notepad. Apparently, the problem was that I used the wrong apostrophe, of all things.

The offending apostrophes exist on the ‘ifconfig’ lines in the /etc/rc file, here:

When I edited this file in Notepad, I used the apostrophe that exists on the quotation mark key on the standard US keyboard layout. As Chris showed me, I should have used the reverse apostrophe instead, which is colocated with the tilde (~) above the tab key.

So the proper /etc/rc file looks like this:

Notice the backward tilt of the apostrophes here. After a reboot with the proper symbol, the IP settings stuck. Even while editing the /etc/rc directly within Data ONTAP via a console session, one can still input the wrong apostrophe. I also used Notepad++ with the same results. I don’t necessarily suggest not editing NetApp configuration files manually, but you should know the intricacies of doing so. Then again, running setup again for interface groups shouldn’t harm much. Setup keeps your previously entered values so you should be able to skip right to what you wish to edit without affecting other settings. Cheers!



3 Comments on “Where am I? It’s dark and I’ve lost my network settings! How innocuous editing of NetApp config file can lead to lost IPs”

  1. True, setup is helpful to retain some of the settings and to make quick updates. But being able to manually edit those files (and understanding what those files do) is almost a black art these days. Dark wizardry! I encourage you to take the time to really understand what those files do, and how edits for them work. Grab the NetApp simulator to test it out.

    And start learning 8.1 Cluster Mode if you are hot for storage and ready to learn more 🙂 Wave o’ the future!

  2. Thanks for reading, Mike. The screen shots above came from the NetApp simulator. It was easy enough to duplicate the issue I ran into at work with the simulator. Also, the shared storage in my test lab comes from two simulators. It’s an excellent learning opportunity.

    Chris has been reading up on Cluster Mode and running the Cluster Mode simulator for a job he’s looking into back in Michigan. He says it’s very different from 7-Mode.

  3. Parikshith Reddy says:

    Did you save the /etc/rc file by doing wrfile /etc/rc before reboot? Because changes made to ifgrps outside the setup script are not reboot persistent , unless you save them using wrfile /etc/rc cmd. From what I’m seeing in the above /etc/rc you could have gotten away by just specifying ifconfig ifgrp name ,ip address and MTU settings instead of specifying the host name . That would assign the IP address to the ifgrps. I Always use wordpad or notedpad++ when making config changes , I always type my commands in notepads++ and paste them to the controller. Never use notepad 🙂

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