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

On 1/19/2021 6:37 PM, Pete Helgren wrote:

Once again to you Patrik and the good Dr Franken, many thanks.  I am ALMOST there.

Going back to your comment Larry:

"So the Client and Server thing will make sense once you complete creating the first partition."  - So, I can skip the SCSI adapters for the IBM i partition I am creating first?  And, further (perhaps wrong) you suggest that when I create my first Linux partition THAT is when I'll create the SCSI adapters, Server and Client, and use them to connect to the NWSSTG on IBM i ?  Or do I create the SCSI Server adapters now and the clients later...just didn't quite grok the idea completely....

Yes you can skip them initially but need them before you create the first Guest. You can certainly create the Server vSCSI adapters on the IBM i partition straight away. They will do no harm and then they are there. You do need to think about how you're pairing up the adapters though between the host and guest though so you get the numbers correct.

Once created on IBM i they will show up under WRKHDWRSC *CMN (Not *STG where you might expect!) and those CMNxx numbers are used in the CRTNWSD command.

Finally, last page on creating the profile:  Tagged I/O  (vs I/O)  I selected the I/O (basically, all of it for IBM i) and when I arrive at the "Tagged I/O" screen I am able to select 1 of the 2 SAS RAID adapters for load source.  I assume they are redundant so I can choose either, or do I need to do more research (or skip it).  Likewise similar questions for "Alternate restart device". Console is flagged as "Management Console" and I don't know what to set "Alternate Console" and "Operations Console" to (so many consoles, so little time....)

Yes either adapter is fine for the load source.

Alternate restart is optional unless you are re-installing IBM i so either adapter works there as well.

Console as HMC is good and the last two can be left open as they are rarely used.

- L

That's it.  With some answers I can push the big button....

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

On 1/19/2021 7:44 AM, Larry "DrFranken" Bolhuis wrote:

On 1/18/2021 9:49 PM, Pete Helgren wrote:

Yes, virtual HMC it is....

Starting on the "dumber than a bag of hammers" questions now. Assumption: I am creating a NEW IBM i partition so that not every resource is allocated to it

First you are creating a new PROFILE for the existing IBM i partition. It will not need to be re-installed and you will lose nothing. Perhaps semantics there but key.

1)    Processors:  I gotta admit, this always threw me, even with the JS12 and VIOS.  I am assuming that I want one dedicated processor for IBM i which it is licensed for. Correct?

Correct. Unless you intend additional IBM i partitions then dedicating one processor to IBM i is the correct answer. You have three more to share among the Linux boys.

2)    Any advantage to shared memory vs

IBM i doesn't support shared memory.

3)     On the I/O page:  Is there any reason I *wouldn't *want to include all the physical resources like Gigabit Adapter and the two SAS RAID adapters? Again the plan here is to carve out a couple of Linux LPARS after I free up some resources.

Fore sure you'll need the SAS RAID cards or IBM i won't be able to see the disks, and it's just not itself when it can't find the disks. :-)

If there is only one Ethernet adapter then you'll need that for sure. You will use one port on there for IBM i and one port to bridge to the Linux guys. This partition will be the host for the other guys so he will own the lions share of that. However you COULD add more  Ethernet adapters and let each Linux guy have one. That's wasted money though IMHO.

4)    As I ponder creating this new profile, how will this affect the existing resources on the IBM i?  Most notably, the Ethernet adapters that currently exist.  Do they lose the underlying resources since I am now creating a new virtual resource for it? Just wondering if when this guy IPL's if it will be accessible....

No change. You're allocating the stuff it needs to run. Despite the new profile all that hardware will be the same stuff, in the same slot, and importantly with the same serial number and thus will report in as the same resources. So he'll be happy.

That's only the first few dumb questions....I noticed that the SCSI adapters have a "Server" or "Client" option (I'll assume SERVER although the document I am looking at says server and then later on talks about creating a client SCSI....).  And, the checkbox next to this adapter is required for partition activation?

So the Client and Server thing will make sense once you complete creating the first partition. IBM i is the host partition so it will have 'Server' adapters. They will 'serve up' disk to the Linux guest partitions. You'll want to be specific when you create those and point them at a specific slot (I'd use 2 or 3) on the guest and specify the guest partition that will use this adapter. Note that partition number is a drop-down and it will be blank because you dont have those partitions yet but you can put in a number there and it will take it. So if your first Linux guest will be partition number 2 then enter 2 for the partition number. Remember IBM i is partition number 1.

The Linux partitions will have Client vSCSI adapters that will point back to the matching Server adapter on IBM i. Again this is done by slot number and partition number. It's rather like connecting a SCSI cable between the correct drawer of drives (IBM i) and the RAID card that Linux owns. Get it wrong and you'll see the wrong disk(s) or no disk(s) at all. :-)

Just slightly advanced but I like to create a PAIR of host adapters and PAIR of client adapters for each guest partition. One is used for DIsk, disk and only disk, never anything but disk. The other pair is used to share virtual optical and tape. You may not use Tape with Linux but you will use virtual optical to install the critter most likely. Having those separate means you can vary off the one used for optical without clobbering Linux.

Linux will only have a virtual network adapter in the same VLAN as the one you created on IBM i. It will NOT have the box checked for 'Access External Network' - only IBM i as the host gets that box checked. This box triggers promiscuous mode on the virtual adapter so that the bridge will function.

More smart answers later. :-)

    - L