Best Practice running Linux as a VM

[Troy_Clavell]

We are a Wintel shop and have decided to start looking into supporting Linux guests. I have no real knowledge of linux and how it runs as a guest OS. Are there any best practices for setup, configuration and performance tuning surrounding Linux?

I've found a couple documents ( and ) , but wanted to get some real life opinions. Also, I know this is a broad question, but what is the typical Linux VM deployed at as far as resources. Would a 2vCPU 4GB RAM be a good default setup? I know most answers will be "it depends", but I'm a real novice with linux so all suggestions and critiques are welcome.

Our environment:

vCenter4.0.0U1

ESX4.0.0U1

2 8 Node Clusters on IBM x3650 M2 Intel x5570 (16 logical Processors and 128GB RAM per)

Emulex HBA's connecting back to a Hitachi USPV

More information can be provided, if needed

Thanks again!

[weinstein5]

The one thing I would say is to follow the same vCPU rules as you owuld with Wintel boxes - start with one -

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[sketchy00]

I agree with weinstein5, definately just start with 1 vCPU, with 512MB to 1GB of RAM. Adjust upward if you need to, but since your Linux VM swap partition can sometimes be based on the amount of RAM you allocate, changing this around too much might lead to a weird error now and again. 1GB is fine.

We have several Linux VM's for our software dev team. 1vcpu and 1GB is plenty, like many of the Windows VM's are hovering way down low when it comes to actual utilization. We also have dedicated Linux VM's built specifically to perform code compiling. These are the workhorses, and will vary in their needs based on whats being done. I've posted some info about these at:

http://itforme.wordpress.com/2010/03/08/comparing-nehalem-and-harpertown-running-vsphere-in-a-produc...

and...

http://itforme.wordpress.com/2010/01/03/resource-allocation-for-virtual-machines/

These were just my own observations, so you may see different results.

[Troy_Clavell]

Thanks gents! Yes, I should have been more descriptive in my wording. A 2vCPU 4GBRAM guest would be considered a "high end" VM in our environment. Typically our Windows OS guests, get 1vCPU and 1 - 2GB to start. Sounds like it really isn't much different whether Linux or Microsoft in resource assignment.

[weinstein5]

Yes Troy Linux is your friend - do not fear the Red hat - :smileysilly:

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[AndreTheGiant · Accepted solution]

I also suggest to use supported distribution (just to have support is something goes wrong) and always install the VMware Tools.

Do not use VMI on 32 bit, cause in the future will be removed.

You can find also a lot of tuning, like this:

http://www.fewt.com/2008/06/performance-tuning-vmware-server-on.html

But I've not seen big difference, so I suggest to keep it simple and just install the VMware Tools, use supported distro, make a good VM design (minimum number of vCPU, right Mem, ...)

Note also that Linux usually use the vRAM in an aggressive way (compared to Windows 2003).

Andre

[Troy_Clavell]

Thanks all! I think that pretty much clears up all my doubts