How to install multi-ISO systems in VMware ESXi

Updated: July 9, 2011

After several of my readers sent me emails asking me about this scenario, I realized it was not as trivial as I thought it would be. For some reason, installing operating systems that require more than one ISO image turned out to be somewhat of a difficulty for quite a few people. Not to worry, we'll get this thing sorted out soon.

In this short tutorial, you will learn that treating virtual CD-ROM devices is absolutely no different from using physical CD/DVD tray. When it comes to installing operating systems that span over several files, the core concept remains unchanged. However, instead of working with actual hardware, you work with software. That's all.


Test case

Let's say you want to install one of the latter version of CentOS, at number 5.5, which comes as a big, handsome set of no less than eight ISO image files. You can burn these to CDs and then break in the eject button on your CD tray. But what if your ESXi machine does not have a CD tray, and what if you are connecting remotely and can't have physical access to the box? You will have to work with ISO images.

All right, let's see how this can be done. First, you get a prompt from your virtual machine installer that it require a new CD in its tray.

New CD required

Second, you need not disconnect/connect your CD/DVD device. It remains connected. The only thing you have to do is edit the virtual machine settings and change the ISO image. As simple as that.

Edit machine settings

In the Properties window, under CD/DVD drive options, simply change the Datastore ISO file you are using. This can be local or remote storage, it makes no difference. For all practical purposes, your virtual machine will think you're just swapping discs in and out.

CD-ROM settings

Device options

Choose the right ISO file:

Choose CD

Once you finish clicking OK a few times, the new image will be mounted and ready for use. Resume your installation as you would with a physical installation. Problem solved.


There isn't much left to say. Sometimes, trivial things may appear to be difficulty or convoluted to get setup and running. Sometimes, trivial really means trivial. While the overall installation process from multiple ISO images via remote connection to a hypervisor is not an ordinary thing, the procedure is quite straightforward. You must need to change the pointer to the correct ISO file in the datastore and let the virtual machine guest operating system continue its work.

That would be all. If you're interested, you may also want to take a look at my cloning tutorial and the tips and tricks guide for ESXi. Stay tuned for additional articles. We have yet to unravel the secrets of the VMware command line. That should be interesting.


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