An Unusual VIOS Install

Edit: The link to the NIM document still works. Getting the mksysb file is easier now.

Originally posted January 25, 2011 on AIXchange

I had an interesting experience with a VIOS installation recently. I’m curious if anyone else has seen something similar. Maybe I just had a bad day.

When I do a NIM install of a VIOS on a new system, I typically refer to this documentation, which outlines a nice way to get the mksysb file off of the installation DVD to use with the NIM server.

The document states:

“Copy the VIOS mksysb image from the CD to your NIM master:

“Mount the VIOS base CD and copy the VIOS mksysb image from the CD (in /usr/sys/inst.images) to your NIM master:

# mount -o ro -v cdrfs /dev/cd0 /mnt
# cd /mnt/usr/sys/inst.images
# cp mksysb_image /export/mksysb/mksysb_image

“If using VIOS 1.5 or higher media, the mksysb file may be split into two parts. To combine these two parts and copy them to hdisk, run the following:

# cat /mnt/usr/sys/inst.images/mksysb_image
/mnt/usr/sys/inst.images/mksysb_image2 > /dir/filename

” *** You can substitute any path you would like to save the combined mksysb image, for ‘/export/mksysb_image’.”

Why would I use NIM to install VIOS if I already have the installation media in hand?

With some IBM Power Systems models, you can get an optional split backplane. This allows you to set up multiple partitions with their own disk controller and disks. With some of these models, however, the DVD drive can only be accessed only by one of the disk controllers. So when the other partition boots up, it cannot see the DVD. This makes it difficult to load that second VIOS on that second set of internal disks, since they cannot see the VIO install media.

I’ve seen people load VIOS to one internal disk and then, when that installation finished, pull the disk out of the first controller and put it into the second controller. Then they reload VIOS onto a disk that they put into the original disk controller. This works, but I don’t think it’s a very clean method; you end up with defined devices on your VIOS that are no longer seen by the operating system.

My preference is to load VIOS and then immediately create a client partition and make it my NIM master. Once I have this NIM master, I define the VIOS mksysb image and use it to load any other VIO servers in the environment — just what’s layed out in the aforementioned document. With the NIM  server there, loading the rest of the client partitions is trivial — at least it usually is.

In this case, however, the issue was that the VIO servers that I loaded from left me with a server at version 2.2.0.0 instead of 2.2.0.10 like I was expecting. Maybe it was bad media, or maybe I just fat-fingered something. At least the solution was simple enough. I just took a mksysb from my clean, newly installed VIOS with the command:

backupios –nomedialib –mksysb –file /mksysb/vios.mksysb

This command excluded the .iso images I’d copied into the /var/vio/VMLibrary (which is my virtual media repository).

I copied that mksysb image over to my NIM server and created my spot. The other VIOS installed as expected.

So has anyone else seen this issue when copying the mksysb file from the install media?