Could a vanilla VIOS installation be simplified?
AnthonyEnglish 270000RKFN Visits (10037)
A vanilla installation of the VIO server is very easy - once you can get the LPAR to access the installation files. But that's the part which can be unnecessarily cumbersome and time consuming.
Sure, you can use a physical Virtual I/O server installation DVD, but that means getting the DVD to a data centre - and probably you with it. Now if you're in a lab setting, or have a data centre across the floor from where you sit, that may not be any issue at all. But for many of us, getting into a data centre is harder than getting into a high security prison (other than the normal procedure, which in both cases unfortunately involves criminal activity). By the time you get security clearance and are physically present, you can write off half a day. What's more, it's half a day of your dedicated time, because you won't get anything else useful done. And that's not taking into account the time and energy involved in a long drive or a flight as well if the data centre is not in your neighbourhood. All for the sake of a virtualised system, with lower TCO and a greener solution than using dedicated hardware for each AIX system.
Getting past the media
Suppose you do get the media, allocate your physical adapter with the DVD-ROM to the VIO Server LPAR and then boot off it. Fairly straightforward from that point. But then, after a successful first install of the VIO server, you have to remove the slot containing the adapter for the DVD-ROM, assign it to the second VIO server, and then build that VIO server, and then eject the DVD. Then you can leave the data centre and do the rest remotely.
When you've made it to finding the VIOS installation source, you can pretty easily find your way through the SMS menu options, especially if you've got experience building AIX LPARs, but getting to the VIOS installation "media" - is still a big challenge.
Now if you don't use physical media, you still have to download the installation files and find yourself an FTP server or NFS server, but that is not dedicated time. You can set off the download ahead of time, and you're able to devote yourself to something else (or nothing else, for that matter). Anyway, even counting the time it takes to arrange downloads and copy files to FTP or NFS servers, it still doesn't compare with a trip to a data centre.
"Hasn't this loser heard of NIM?"
Now if you're thinking: "why doesn't that whingeing Aussie just set up NIM?", the answer is in the documentation for installing a VIOS via NIM. It's not the quality of the doco I'm complaining about: it's the quantity. There's just too much to learn, and it's complex. For someone who has never installed NIM before it's a huge amount to digest when you just want to do a basic installation of a VIO server. Even for people who have worked in AIX for a long time, if they haven't used NIM for a while (or at all), it's not something they can pick up again in 5 minutes.
Nigel Griffiths presented a webinar this week on VIOS installation. In that he says about installing the VIO Server:
"Could use NIM - only for the NIM experts - IMHO."I couldn't agree more.
I challenge anyone who hasn't a lot of NIM experience to set up NIM unassisted and install the VIO server unassisted (apart from the documentation). You might trace your way back to the excellent NIM from A to Z Redbook for AIX 5L, but then again if you're installing Power7, with AIX 7, you may not be too confident trawling through an AIX 5 Redbook (even though it's almost all helpful and relevant). You might not even think of it.
A remote, vanilla installation doesn't have to be that hard!
HMC installios command
There's another option for installing the VIO server - using the HMC command installios. That requires command line access to the HMC, but at least you can do it remotely by downloading the VIOS installation file in ISO format and mounting it via NFS. Much less to set up than a fresh NIM installation, and Rob McNelly explains how it can be done. Doing it this way, you can say good-bye to installation media and build a Power system without physical access to a data centre.
Yes, installios is an option, but pretty rarely used, I'm told, and it's only really for an initial VIOS installation. If you want to do a migration, or for some other reason boot the VIOS off media, you can't do it via the HMC.
Virtual Media Repository
As you know, I use the Virtual Media Repository (also called Virtual Media Library) a lot, and it's quick and easy to master. I think you can learn pretty much all you need to know about it through a short article or by using help on the padmin VIOS restricted shell.
You can use the Virtual Media Repository to download images in ISO format and then use them to mount onto virtual clients. That makes it a simple task to build a new AIX system from scratch, or from a mksysb backup of another AIX logical partition, or even create a file of anything into ISO format and make it available, all without using physical media.
But how do you mount an ISO image for the VIO Server to use? You can boot a virtual client off a Virtual SCSI (VSCSI) adapter and have an operating system built in 20 minutes or less. Why can't you boot a VIO server off a VSCSI adapter? After all, VIO servers can have VSCSI server adapters, and VIO clients can have client adapters. Wouldn't it be good the other way around?
"But ... but ... but it's a VIO Server!"
Yes, yes. I know the VIO server is a server. But you can still give it client serial adapters. Why not client VSCSI adapters? How do you get the VIO server image to map to that VSCSI client adapter? I don't know. Perhaps the HMC (or SDMC) would be a natural fit for it, similar to file-backed devices.
Now, you might be wondering, dear reader, whether that AIX guy Down Under is still on the same planet as you. But bear with me a moment more, if only for old time's sake.
Virtual ethernet, but not VSCSI
Alright, I'll grant that giving the yet-to-be-installed VIO server its own VSCSI client adapter to boot from is a bit of a pipe dream. It can boot from an ethernet adapter, but you still have to have something like NIM or the HMC to present the installation media across the network. So I'll resign myself to the fact that at the moment, I have to install VIO server 1 the current way.
Wouldn't it be good at least if you could install VIO server 1 (with NIM, or physical media, or via the HMC installios command), and then do the other VIO server via the Virtual Media Library? And if you ever need to migrate your VIO server (the underlying code for VIO server version 2 is still AIX 6, but one day it will go to AIX 7), it's back to physical media or upgrading NIM and then learning how to do the migration steps. Same difficulty if you happen to lose your padmin password (or, more likely, lose the sys admin who knew it).
VIO Server as a Virtual Media client
Imagine being able to do a migration (upgrade) of two VIO servers where they could load ISO images from each other's Virtual Media Repository. You could then upgrade each VIO server in turn by booting off the new VIOS server installation image presented via the other VIO server's VM Repository.
If you were doing that with NIM, you'd have to commit yourself to migrating NIM first, so that it is at least at the same level as the new VIOS' underlying AIX level.
If only you could boot the VIO server off the VSCSI adapter - maybe loading the installation media from another LPAR somehow. And you could even do it through a nice GUI interface, such as the HMC or SDMC.
ISO image access for the VIO server
Now you can load ISO images for use by a VIO server (as opposed to the VIO clients) another way: with the AIX loopmount command on the VIO server. To do that, you'd need to log in as padmin on the VIO server and then go to the full root shell by running oem_setup_env. It's not too hard to do but you can't boot off the image, as when you reboot the VIO server, you lose access to the mounted file systems, including the loopmount-ed ones.
NIM has its uses
I don't mean to say that NIM is of no use at all. It can come in very handy for installing software across multiple LPARs, and for migrations using nimadm - which can reduce outage time. NIM is also used by IBM Systems Director. What I'm trying to point out here is that the Virtual Media Repository is so easy to learn, and easy to use, letting the VIO server be able to boot from or load an ISO image via a VSCSI client would be an altogether Jolly Good Thing.