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I'm getting new VMs built for development and staging environments, and was wondering whether there are compelling reasons for or against using the linux-virtual package on all of these images.

Do the -virtual kernels have different tuning? Do they have tools that make the suspend/wake-up better/safer?

Bryan Agee
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1 Answers1

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Since 12.04, there is no difference between the Desktop linux-generic and Server linux-server kernels; they have been merged. (Source; see here for why this was done.)

The virtual kernel differs only in the number of included drivers. It only includes "the necessary drivers to run inside popular virtualization technologies such as KVM, Xen, and VMWare. ... Other than that, all other options are identical between the generic and the virtual kernels."

In practice, this means the -virtual kernel image is smaller, and may also take up somewhat less room in memory (fewer built-in modules/drivers). The savings are probably in the single-digit megabyte range, so it won't make a difference for most VMs.

Server and Desktop kernel differences before 12.04:

Before 12.04, the differences were:

  • The Server Edition uses the Deadline I/O scheduler instead of the CFQ scheduler used by the Desktop Edition.

  • Preemption is turned off in the Server Edition.

  • The timer interrupt is 100 Hz in the Server Edition and 250 Hz in the Desktop Edition.

ish
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andrewsomething
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  • Does this mean that, if I have linux-kernel-virtual I don't need to install open-vm-tools package to get VMWare advantages, or is that separate from the kernel drivers? I'm assuming this only impacts thing like NIC card drivers and doesn't get into deeper things like memory utilization, etc. – flickerfly Jun 30 '14 at 21:43
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    I think no. VMWare is enterprise supported and hence not included in default kernel. But you will get base KVM, Xen support and maybe kernel patched for VWare advantages. – Gonzalo Aguilar Delgado Feb 12 '15 at 12:31