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
Solved

Overhead with VM's

Posted on 2010-08-30
7
614 Views
Last Modified: 2012-08-14
Hi

We have an application (Finance1) that we are looking to deploy within our network. As is our current strategy for most things, we will deploy the app on VM ESX 3.5 guests rather than physical boxes.

The vendor has various performance calculators, hardware calculators, storage calculators to gauge the hardware necessary to run Finance1. We enter in data for some fields related to usage (number of users, level of activity they are carrying out etc) and also the hardware specs of the machine (physical memory, CPU types etc) and the calculators will provide info back on whether this would work adequately or not.

Problem is, their calculators are all based on physical servers not virtual ones. I'm going to get back to them and ask them, but in the meantime I was wondering - should this sort of calculator apply to both physical and virtual servers? Or do VM guests' resources have an overhead for running as VM's (e.g. some percentage of resources being eaten up by the host etc) that would make them not accurate?
0
Comment
Question by:kam_uk
7 Comments
 
LVL 5

Accepted Solution

by:
jlanderson1 earned 100 total points
ID: 33560642
The values should be the same for VM's and physical servers.  
0
 
LVL 4

Assisted Solution

by:Zupreme
Zupreme earned 100 total points
ID: 33560653
The exact same considerations apply whther you are talking about physical or virtual machines, with one caveat:  if this is a critical application make sure that you atually provision those resources as dedication for your VM (as opposed to only making the resources available to the VM) otherwise an activity storm on any other VM hosted on the same box will degrade performance of your critical application.
0
 
LVL 3

Author Comment

by:kam_uk
ID: 33560839
Thanks guys..

Ok - let's say the calculator asks me to enter in the type of processor the server is using. I enter the type of processor used on the ESX host, and since I am only giving the guest 1 CPU, I enter "1" as the number.

Surely, this is not correct? The virtual CPU that I have assigned the guest and the actual CPU of the host cannot be compared in terms of resources to the guest?
0
Ransomware: The New Cyber Threat & How to Stop It

This infographic explains ransomware, type of malware that blocks access to your files or your systems and holds them hostage until a ransom is paid. It also examines the different types of ransomware and explains what you can do to thwart this sinister online threat.  

 
LVL 119

Assisted Solution

by:Andrew Hancock (VMware vExpert / EE MVE^2)
Andrew Hancock (VMware vExpert / EE MVE^2) earned 100 total points
ID: 33560909
The first thing you need to establish, is whether the vendor will SUPPORT the application on a Virtual Platform, VMware, Microsoft, Citrix, Sun etc.

If not you'll then need to make a decision, as too whether to risk this move or not.

Some Vendors I work with at present will NOT SUPPORT their applications on any Virtual Platform. This make is very difficult when their application (DB etc), has faults, because they refuse to support it, unless we can prove the same fault occurs on a physical platform.

Sometimes this is because the vendor does not have any specfic knowledge, training or testing of their product/application on a virtual platform. Ask the vendor if they have any clients that currently run on a virtual platform, and what specs are they using, ask for their telephone number and talk to them about any issues they have!

0
 
LVL 3

Author Comment

by:kam_uk
ID: 33560997
Yep, it's def supported to run on virtual :)
0
 
LVL 63

Assisted Solution

by:SysExpert
SysExpert earned 100 total points
ID: 33561007
actually, that depends on whether you have multiple processors/cores.

If the core is not shared by any other guest, then the value should be the same whether a VM or Physical since the Host does not use much capacity.

I hope this helps !
0
 
LVL 2

Assisted Solution

by:ddawson100
ddawson100 earned 100 total points
ID: 33564074
The guest OS isn't going to be aware of whether it's running on physical or virtual hardware so you can use the same formulas when planning.

As you may be installing this guest on a common pool or common host you'll also want to be sure you're not already pegged on performance. Now is the time to check your utilization using the charts or esxtop/resxtop for realtime counters. You'll want to ensure a smooth implementation rather than troubleshoot performance later.

Finally, since your vendor will support this on a virtualization platform they may have guidance on how to reserve resources (for CPU and memory) or target the best disk array (RAID levels and current utilization levels).
0

Featured Post

Best Practices: Disaster Recovery Testing

Besides backup, any IT division should have a disaster recovery plan. You will find a few tips below relating to the development of such a plan and to what issues one should pay special attention in the course of backup planning.

Question has a verified solution.

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

Suggested Solutions

If we need to check who deleted a Virtual Machine from our vCenter. Looking this task in logs can be painful and spend lot of time, so the best way to check this is in the vCenter DB. Just connect to vCenter DB(default DB should be VCDB and using…
HOW TO: Connect to the VMware vSphere Hypervisor 6.5 (ESXi 6.5) using the vSphere (HTML5 Web) Host Client 6.5, and perform a simple configuration task of adding a new VMFS 6 datastore.
Teach the user how to configure vSphere Replication and how to protect and recover VMs Open vSphere Web Client: Verify vsphere Replication is enabled: Enable vSphere Replication for a virtual machine: Verify replicated VM is created: Recover replica…
This Micro Tutorial walks you through using a remote console to access a server and install ESXi 5.1. This example is showing remote access and installation using a Dell server. The hypervisor is the very first component of your virtual infrastructu…

791 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