[jfclarkjr]

Hi all,

We are having debates at my company on how to roll out IBM 52A servers with VIOS to our customers. Should we use dual VIO servers or is it considered pretty safe to go with just a single VIO Server? The reason it's an issue for us is that we'd like to avoid having an HMC, and rely solely on the Integrated Virtualization Manager. But off course, having dual VIO Servers would require the HMC...

I'd really love to hear anyone's opinion on this. Is anyone using a single VIO Server implementation in a production envoronment? Has anyone heard of the future trends for the HMC?

Thanks in advance,

John

[Administrator]

How would you do VIO OS maintenance without risk with only one VIO server?

[hservadac]

I think dual VIOS is out of scope in entry-level servers.
One of my customers has a very reasonable paradigm:

Entry Level servers (550Q - NON-Production Environments) :
VIOS / NO HACMP
High End Servers (they skip 560Q - Production):
570 -> Hardwares Level Partitioning / Some servers use VIOS (2 in cluster)
590 / 595 -> Hardware Leve Partitioning + HACMP

Redundant VIOS is useful in redundant hardware. Maybe you can setup a VIOS with enough availability :
2 NICs , defining 2 Virtual NICs to every LPAR
Mirror your VIOS installation
2 FC Cards - If you are paranoid enough, you could use LUNs from both adapters and make a mirror in your AIX/Linux between them.
2 RAID Adapters (IOA Level Mirror)

Remember to user enough processor and memory for your VIOS.

Hector Servadac

[ross.mather]

Dual VIO servers would be tricky in a 52A as you would want your VIO server to boot from local disks (for eventual SAn debugging) and the 52A only has one disk controller.

[jfclarkjr]

Ross,

I've been told that the p5 52A can be set up with 2 disk controllers. The POWER 6 seems to be a different animal. Are you referring to a POWER 6 52A when you say it only has one disk controller?

John

[duke900ssd]

a) I do not think there is a model 52A that has a power6 cpu.
Known p6 models: MMA / E8A / E4A

b) I think the 52A has a single internal dual channel scsi adapter with the option of a split DASD backplane, this dual channel adapter is a single 'adapter' and so can only be controlled by a single LPAR / VIOS.

There may be the option to cable the internal adapter to one of the dual DASD backplanes and then use a pci scsi adapter to control the other but I am not sure, ask IBM pre-sales tech support what the options are because we could all spent the rest of our lives searching the IBM Info Center and never find the answer.

[ross.mather]

Download and try the system planning tool from the IBM website. That will let you see if you can get dual VIO servers out of a p52A. The smalle box that DEFINATELY has dual SCSI adapters is the p560Q,

[Administrator]

I think the general consensus can be summed up like this: you can run a single VIO server on a p52A, but it's not recommended for a production environment.

Best practices for a production environment is a dual VIO server configuration which would allow maintenance on one VIO server without affecting the served LPARs.

[jfclarkjr]

Thank you all very much. The responses have been very helpful!

John