VPar Software Pro's and Con's?

[Steve Bardell]

I was wondering if anyone could explain the advantages of using the VPar software that HP offers, vs. adding another server to my environment.

Are there any Performance or cost advantages to using VPar?

[Stefan Farrelly · Accepted solution]

Advantages;
1. cheaper than buying a new server (a lot cheaper!)
2. makes good use of any spare cpu's and memory on an existing server that is underutilised - just vpar it to create a new server.
3. free versions allows 1 vpar with 1 cpu, the rest have to go into a 2nd vpar. No more. A bit unflexible.
4. a fantastic way to have spare test servers for development or testing without breaking the bank. We managed to find spare cpu's/disks and enough ram on a few production servers to split off a 2nd vpar on each (with only 1 cpu) but thats enough to have some test and development servers - and it didnt cost a cent.

Disadvantages;
1. the free version is a bit limiting, full version is like well over $1000 !
2. have to logically divide a server into 2 - by io bus/channel, eg. must have 2 disks - one for each OS, on a different bus.
3. usually need more ram as splitting an existing server into 2 needs a lot of ram (say double!)

[Robert Thorneycroft]

I have asked HP reps the same question, and when you nail then down it boils down to no-one can see any benefit! It is cheaper to but 2 small servers than 1 large server, so there is no cost benefit and you are putting all you eggs in one basket.
The only slight benefit that anyone has been able to point out so far is that the number of cabinet units the larger machines take is not quite twice the smaller, so you should be able to deploy more machines in the same floorspace. If floorspace is not an issue however I have so far drawn a blank!
If anyone from HP reads this and can come up with a valid answer I would also be more than interested to know.

[Jean-Louis Phelix]

Hi,

Stefan was clear,

I can also add the integration with WLM to allow a very flexible optimization of CPU resources (fully automated !). I also know a customer who have a test system from january to november, but suppress this Vpar during december to improve performance of all closing year batchs. Really 2 major points are flexibility and price ... Adding a Vpar is cheaper than buying another box.

For the con's ... Some are only temporary (hangs at reboot, not possible to dynamically reallocate memory, ...), but the biggest one for the moment seems to be that an HPMC on some parts of the box could lead to the failure of all Vpars, not like hard partitions.

Regards.

[Steve Bardell]

These are all extremely helpful to me, if there is anything else that anyone can add, it will be much appreciated. I have assigned everyone 10 points, because these are all great answers so far. Thank you very much.

[Stefan Farrelly]

Jean-Louis mentioned possible problems with hangs, HPMC's, crashes etc. I hope this doesnt give the wrong impression that VPARS may cause these. Our N's and L's are ultra reliable, Im trying to think of an ocassion one actually did any of the above, and since weve been runing vpars on a few of them they are still ultra-reliable - weve never had a hang, crash or HPMC on a vpar server so no decrease in reliability there.

[Jean-Louis Phelix]

Hi,

You're right Stefan, HP servers are VERY reliable and perhaps I was not clear enough :

- hangs are only 'short hangs' at reboot (< 20s) and this should be fixed shortly

- I'm working in mission critical environments, so even if I agree that I've never seen any Vpar related HPMC, it's simply something that could happen on any system. Having Vpar will not increase the risk of HPMC, but the impact could be different.

I really think that it's a wonderful product and last but not least, it's really easy to use ...

Thank you Stefan for your good opinion about HP systems :^) !

Regards