Re: A few more questions about Linux LPARs, HMCs and other items -- MIDRANGE-L

No re-install, not at all.
In your HMC you should see the partition as number 1.

You need to create a new profile for it. When you do so on about the second panel there is a check box 'Use all the resources in the system.' Don't check that! (Currently it undoubtably is.) Then only allocate the memory and processor desired for that.

Once that's created set it as the default profile for the partition.

Now while you're in there don't forget to create the vSCSI host interfaces for the guest partitions as well as the virtual Ethernet needed to bridge to those partitions. And be sure to up the maximum adapters to maybe 100 or so. They consume zip for resources so don't be afraid to go higher than you ever dream you'll use!!

Now Power down the partition (PWRDWNSYS style) and then restart it from the HMC but using this new profile (NOT 'Current configuration' :-) )

And thus there is now resource available for other partitions.
- L

On 1/18/2021 10:59 AM, Pete Helgren wrote:

Great! Just what I needed.....so the next question starts at the top. You said:

"So the likely first step is to create a new profile for IBM i that does not require all memory and all slots and all processors. This leaves resources for other partitions."

YES! Exactly, except, how is that done? That was the missing piece for me. There is a bunch of documentation on how to create/allocate the other resources needed for an LPAR but it is that very first step of creating/installing/whatever the IBM i environment where it doesn't own everything. Can you point me to documentation on that very important first step? Am I going to have to start from scratch and re-install the whole nut to make that happen?

As an aside (future conversation): Is starting with VIOS a better way to go? I am guessing that it ain't free, so that may be my sticking point, but if it makes virtualization easier, it might be worth looking into....

Pete Helgren
www.petesworkshop.com
GIAC Secure Software Programmer-Java
AWS Certified Cloud Practitioner
Twitter - Sys_i_Geek IBM_i_Geek

On 1/17/2021 9:58 PM, Larry "DrFranken" Bolhuis wrote:

OK So lots of questions here, hopefully some information.
First let's discuss the base machine.

Because you have IBM i as a base partition and I suspect you didn't have HMC console listed it's probably that the current partition profile for IBM i specifies 'all resources'. That way if you added a card in an empty slot or added more memory for example, IBM i would see it all right away.

So the likely first step is to create a new profile for IBM i that does not require all memory and all slots and all processors. This leaves resources for other partitions.

Sharing memory is straightforward. Simply don't allocate all of it to IBM i, leave some for other partitions.

Sharing processor is simpler. You have four so let IBM i have the one it's licensed for and allocate the other three to other partitions.

Sharing the network is also easy. Allocate (logically) another port or two on your Ethernet card to a bridge that the other partitions will use to access the internal network. You'll also need a new virtual Ethernet card on the i profile with 'access external network' box checked. Those two items will form the bridge - external to internal.

Sharing disk requires just a bit of effort. IBM i owns it all today and you likely don't have any additional RAID cards or drawers full of disk unless you have your disk on SAN. So you'll need to CRTNWSSTG to create the virtual disks to share with your guest partitions. Also CRTNWSD to describe the connection to those guest partitions and then ADDNWSSTGL to tie the storage to the server. Of course to do that you'll also need another addition to the IBM i profile which is the virtual SCSI connection to the guest which will be used with the CRTNWSD command.

Now that's the 50,000 ft flyover.

There is another complete plan where VIOS is installed and owns all the disk and IBM i becomes a guest of VIOS. There are reasons for either of these being better choices but that's an entire presentation. :-)
- L

On 1/17/2021 5:46 PM, Pete Helgren wrote:

Pondering starting down the LPAR road now but I have a few conceptual things I need to sort out first. I have had a couple of LPAR experiences in the past but not with an HMC so I am a little uncertain on how to proceed. A LONG time ago I used VPM to create a Linux partition. As I remember it, it was a little un-intuitive but it worked. On my JS12 blade, it was a whole lot easier. I used the IVM in VIOS to carve up the available disk and CPU's. With the vHMC, I really haven't used it to assign anything. The 9009 was installed using the console so I didn't have to decide how much disk, memory, etc was allocated to IBM i. So, like I said, I just need to get my feet on the ground with concepts.

Some of the stuff I have read seemed more like using a VPM and yet there are references that the HMC makes its more like the IVM. So, I'll start with a few questions:

1) The 9009-41A I have has 4 cores, three of which are idle. Are those cores available for non-IBM i workloads? Do I have to use the $PEND MONEY command to activate them?

2) Was there an essential "first step" that I should have taken if I was planning to run non-IBM i workloads along side the IBM i one? Something tells me that everything should be virtualized to be able to "slice and dice" the 9009 to different workloads. If so, does VIOS need to be the underlying OS with everything on top of that?

Several folks suggested online resources to create the LPAR. There just seems to be a few different approaches to how to handle the hardware side of things. I can see where I could "steal" existing resources from the IBM i side, but my hope was that I could utilize the unused cores in in the Power9 and also, if necessary, allocate disk to the other partitions. Not seeing a way to do that.

I saw posts from Michael Quigley, Patrik Schindler, Steve Pitcher, and Jack Kingsley that filled in bits and pieces for Michael when he was contemplating his Linux LPAR but it didn't completely fill in the blanks for me. Answers to the first two questions will determine my next step (and questions).