How many VMs is too many IYO?

One more than you will actually use.

 

In my day job I work with servers.
How does more than 20 VMs on 4 x VMware ESXi servers sound?

 

No much thing. But are you really going to use all of it unless you're running a lab or server?

 

The only time there is too many VMs is when your machine can no longer handle it.

On my old 2011 iMac 21.5 i5 I would sometimes run 3-4 VMs with no issues, but I also had enough Ram to handle it.

If your machine has 32gb of ram it is very easy to do.

Now if you are planning to do a lot of cpu intensive among all the VMs at the same time, that is where cpu would be an issue.

 

At one point I had MS-DOS/Windows 3.11, Windows 95, and Windows 98 SE all under Parallels on my 2010 MBP.

I say never enough!

(But, seriously, whatever system you have could probably handle those 2 simultaneously, no problem. No version of Windows 9x/ME needs more than 1GB RAM max dedicated to it.)

 

I'd say never too many --so long as you actually use them. If they aren't being use for.. let's say.. 6 months maybe time to get rid of that image.

 

I do almost all of my web development work in Vagrant instances. Every client gets its own VM to keep things isolated. There's no such thing as too many!

 

10 would be not bad.

 

That's funny! You're a funny guy...

 

At the office we're building a whole new virtual environment and I currently have 9 VM's running in VSphere (Vcenter) on a Nexsan with plans to almost double that by the time we're done.

At home, on the iMac, with Vmware Fusion 7 I only have two VM's, Windows 8.1 and Windows 10 (Technical Preview). I do not run them at the same time, only one at a time.

 

I have 10 running on my Mac Pro;
Windows 7
Windows 8
Windows 10 Tech Preview
MS Server 2003
MS Server 2008
MS Server 2012
SQL Server 2008
SQL Server 2012
Cisco CM
Cisco Unity

I obviously don't run them all at the same time, but I've had 5 open without an issue.

 

Hmm let's see....

I have:
Windows 98 SE (just for fun) - 128MB RAM
Windows XP Pro SP3 x64 (for nostalgia's sake) - 512MB RAM
Windows Vista Ultimate x64 (for nostalgia's sake as well) - 4GB RAM
Windows 7 Pro x64 - 4GB RAM
Windows 8.1 Pro x64 - 4GB RAM
Windows Embedded 8.1 Industry Pro (for making images for embedded systems) - 4GB RAM
OS X 10.6 Server (for Rosetta) - 2GB RAM
Elementary Luna - 1GB RAM
Ubuntu - 1GB RAM.

All these on a 27" iMac with 32GB of RAM. I only have 4-5 of them running at the same time though.

 

The limit is not how many you have, the limit will be how many you run in parallel. Your computer will tell you that limit.