Solved

Questions on vmware and virtualization

Posted on 2013-01-14
4
240 Views
Last Modified: 2013-01-15
Hi all ,

one of my customers has these two questions and not sure what the best answer is. Any ideas would be appreciated


Please advise what limits there are in amounts of physical memory we can have in a virtual server.  ( so for example if i have a physical host with 23 GB RAM) how much ram can i allocate to the virtual machines ? Can i create vms and allocate 32 GB of ram on these vms ?
 
In addition if we want the equavalent of 2 Quad Core CPU's does that mean we need to request 8 CPU's? Is that an option?
0
Comment
Question by:c_hockland
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 2
4 Comments
 
LVL 23

Expert Comment

by:Stelian Stan
ID: 38776910
If you have a host with 23 GB of RAM that means that's the maximum amount of memory you have for your VM's.

If you have two quad cores that means that you have 8 virtual available for your VM's.
0
 
LVL 23

Accepted Solution

by:
Stelian Stan earned 500 total points
ID: 38776913
0
 

Author Comment

by:c_hockland
ID: 38776992
many thanks !
0
 
LVL 32

Expert Comment

by:aleghart
ID: 38777695
You can overprovision RAM, hard drive space, and CPU.  If your VMs are running at 2% CPU, 25% RAM, and 25% hard drive space...with no growth projected, and no heavy simultaneous loads.

In an ideal world, you'd be using virtualization to maximize the utilization of the hardware.  If you have 8 Server 2008 boxes at 4GB RAM each, they might only be using 1GB of RAM.

Running out of RAM will cause the host to swap, and the VMs should fare fine.  If the VM guest is provisioned with 2GB and runs out of RAM, the guest will spool.  The host will only see excessive amounts of storage and CPU activity.

Four cores of CPU is a lot.  Have you tried with one first, and monitor the guest & host?  You may be surprised how little CPU provisioning you need.  1 or 2 cores can still run a database, instead of 4 or 8 from the start.

If your host has 24GB of physical RAM, then your guests (in aggregate) can only use that much physical memory before the host will start to swap.  This doesn't limit you to creating only 24GB of VMs.  Each VM can have a different location for swap.  Default is swap stored with the VMDK.  You can move this to a host local drive, local RAID, faster SAN, or local SSD.

I have a Server 2008 VM idling for a dev project that's using less than 1% of its 4GB RAM, and 0% of it's CPU.  Another that's currently replicating a small database is using between 1-10% of the CPU and less than 5% of its 2GB RAM.
0

Featured Post

Get free NFR key for Veeam Availability Suite 9.5

Veeam is happy to provide a free NFR license (1 year, 2 sockets) to all certified IT Pros. The license allows for the non-production use of Veeam Availability Suite v9.5 in your home lab, without any feature limitations. It works for both VMware and Hyper-V environments

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

When converting a physical machine to a virtual machine using VMware vCenter Converter Standalone or vCenter Converter Enterprise, if an adapter type is not selected during the initial customization the resulting virtual machine may contain an IDE d…
In this step by step tutorial with screenshots, we will show you HOW TO: Enable SSH Remote Access on a VMware vSphere Hypervisor 6.5 (ESXi 6.5). This is important if you need to enable SSH remote access for additional troubleshooting of the ESXi hos…
Teach the user how to convert virtaul disk file formats and how to rename virtual machine files on datastores. Open vSphere Web Client: Review VM disk settings: Migrate VM to new datastore with a thick provisioned (lazy zeroed) disk format: Rename a…
This video shows you how to use a vSphere client to connect to your ESX host as the root user. Demonstrates the basic connection of bypassing certification set up. Demonstrates how to access the traditional view to begin managing your virtual mac…
Suggested Courses

617 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question