vmware !! mix linux+w2k on same box or keep separate ?

[Unix Team_6]

Hi all,

we're about to virtualise all our w2k and linux boxes onto vmware. The debate here is do we mix windows+linux guests on the same physical box (proliants) or keep them separate - ie. one set of proliants running esx+vmware+linux guests and one set for esx+vmware+windows guests only ?

What does everyone else do - mix or split ?

We can see advantages to splitting - as our w2k and unix teams are separate, not sure how they will get on if have to share a physical box if and when problems crop up.

Problem is our TDA's have this utopian idea of best design being to mix them!

Thanks.

[Uwe Zessin]

It is not a technical problem to mix different OSes, however it looks like you have an organizational 'problem'.

In that case it might be better to isolate the servers into two (Virtual Center) clusters with separate permissions or even two completely different Virtual Center instances (requires a second license, though).

Is there any SAN involved?

[Ivan Ferreira]

There is no problem on mixing guest operating systems. You should consider the server load and try to balance them.

Also, please ensure to review this link, it's very important:

http://kb.vmware.com/selfservice/dynamickc.do?cmd=show&forward=nonthreadedKC&docType=kc&externalId=51306&sliceId=2&stateId=0%200%208616976

[Heironimus]

The proper design is almost always to mix everything, it will make the best use of your licensing money and your hardware resources. Besides, how can you ask your application owners to share hardware if your own admins can't get along well enough to do it? You're probably already sharing physical facilities and networking anyway, sharing a VMware environment isn't really all that different. You just need to keep everybody informed about changes that may affect them and make sure that VMs are being provisioned appropriately (reservations, priorities, etc).

[Nuwan Alwis]

Wel, i vote for the keep w2k and linux on separate virtual centers. This is only if you have no cost/license/Hw or special Device sharing issues with guest systems. The major advantage of this is single point of administration. Example you can add all hardware which your linux systems required to your guests and deploy all linux boxes on 1 physical server.

The disadvantage i see is if in case you have to do a maintenance on the physical server you will have to bring down all your guests or migrate them to another server.

The bottom line is there is no restrictions or performance issues when you guys using ESX.

FYI,
if you are thinking about xen as a virtualize solution there is a major advantage keeping linux guests on it because most of the new linux distros performs well on xen coz there developed work so(para virtualized).but windows is not designed so except new windows 2008 server.

[TwoProc]

Just my 2 cents - a few considerations - note that they are considerations - certainly not absolutes, there are plenty of scenarios in which the following just wouldn't apply.

Intel hardware is cheap, and since you are virtualizing - and saving even more $$$ - I say go for separate. This way, each team owns its own hardware and performance problem(s). If you're all on the same servers - then h/w and performance is owned by none, and of course, performance issues would be caused by the "other" teams' layout and design.

This leaves each team to be able to figure it's own issues, handle it's own backups, recoveries, down times, service schedules, hardware allocations, aging strategies, etc.

Also, consider that the virtualization software (vmware) would have separate requirements and thus patching and maintentance schedules for supporting Windows (ne: Windows 2000,2003,2007,Vista,Windows 7) would be very different than supporting each Linux server. My guess is that you'd deploy a Red Hat, Suse, or Ubuntu system at the current OS levels, and you'd have no new requirements on those virtual servers from vmware for the next 3 or 4 years or so. HOwever, with Windows and the upcoming OS upgrades you don't have the same scenario. The extended Windows toolboxes and add-ons have more requirements for interoperability than the Linux ones do. For example, I see many improvements in how vmware handles hosted Windows, whereas the hosted Linux systems that I use seem to be about the same. I got the improvements by vmware patches, I didn't really need them for the Linux Os's on my systems.

Also - I think the only way all teams will be happy is if "more than enough" hardware is purchased to share, so that there are few, if any limitations on what virtual servers consume what resources. And Thus, in this case - you've overbought. Consider using the "overbought" budget just to buy separate hardware.

Consider also - pricing on servers have a "sweet spot" - when you buy the largest boxes, you will pay a larger price per amount of horsepower. The mid size boxes have the best tier pricing as they are a more common sales and support configuration across all customers. So, depending on what you need for total hardware, a few more mid sized boxes maybe cheaper than just one or two larger ones. Don't forget to get quotes and pricing on hardware and software support as well, it can change the picture on the TCO for a 3 or 4 year project (both for or against separating the environments, but they both need to be looked at regardless, if your lucky, it may help whichever case you're looking to build).