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I have the following server: Processor: AMD 12 Cores RAM: 32GB Storage: 2x500GB

How many vCPU`s can I create using VMWare ESXi or VirtualBox ? Any other product that you think I should know ? Any recommendations ?

Thanks !

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closed as off-topic by Stephane, Dave M, MDMarra, cole, pauska Nov 12 '13 at 13:29

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Depends totally how much the CPU is used. Basically there is no real limit. Oversubscribing by a factor of 16 MAY be ok IF your virtual machines are "crappy enough". If you go for example for a low end web hoster and every VM hosts 1-3 small business sites, man, the CPU is going to be bored. OTOH I have a database virtual server here using 8 of 8 cpu cores and keeping them busy.

There are technical / recommended limits which you can check at the manufacturer (they vary by version - getting larger in factor with newer versions) but they are technical upper limits.

Generally, thisis an impossible to answer question. I have a lot of virtual serves I expect to rarely spike in CPU usage (mostly: domain controllers, DNS servers) or be low CPU (file servers, heck, even some database servers for lower used websites) and others that really need 1 core per vCore because it is running hot.

Common sense, requirement analysis and a good amoung of guesswork are your scaling guideline here. Add as needed. You likely run out of memory first - I run a similar setup.... now.... on a new server we got online recently... but I have 64gb and that is already taxing - the CPU is not ;)

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It obviously depends on what your going to be doing with them but a rule of thumb is GB per guest, so 6-7 (leaving ram for the host)

you may also want to check out this tool:

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Have you considered answering the question? He does not ask about ram at all, you know. It is there, clearly, in the title. – TomTom Nov 12 '13 at 13:29

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