[ale] Speeding up VMs

[DJ-Pfulio]

Virtualization is an exercise in sharing resources and making management of
those resources as easy as possible.

The single most important item for performance is to re-allocate the virtual HDD
for the VMs. It has gotten better over the years if you don't, but during
installation of the OS, a prebuilt vHDD takes 11 minutes and a sparse
(grow/shrink) vHDD over 30 minutes.  Of course, of your vHDD is on SSDs, it
doesn't matter and I'd use sparse every time.  No SSDs here.  Changing this
setting later is a hassle and forces you to use VboxManage from a command line.
Not _hard_, but that just feels weird on Windows.

Next is to start out without any GPU acceleration enabled, but for desktops,
maximize the available video-card RAM to 128MB.  This will prevent most desktops
from trying to do high-end GPU stuff.  It isn't so bad anymore, but you can
always enable 2d and 3d accel modes later, after you've gotten the VM performing
well for non-GPU workloads. These settings can be enabled/disabled later.

Guest Additions - for virtualbox, installing the guest additions really does
help, but be careful to read the license agreement. It isn't the same as for the
main Vbox program.  There are some nasty bit (last time I read it) that Oracle
had added.

I've run most of the virtualization tools over the years. Used to give
talks/presentation about optimizing performance for VMs internationally. My last
Everything I know about Virtualization talk was in the fall of 2014. Covered
VMware (player, workstation, ESX, ESXi, Server), Vbox, Xen, KVM.
Since around 2013, I've been 100% KVM for production uses.  Haven't powered up
virtualbox on my systems since then. Used Xen for 4 yrs in production, it was
fast and stable, once running, but hostOS kernel updates would prevent guestOSes
from booting a few times yearly.  Never had that issue with KVM (using it since
2010).

If you'd like 1-on-1 help with this stuff, come out any Sunday and sit next to
me with your workstation (or remote connection to the VM system) and I'm happy
to help. For small scale stuff, I don't think anything has really changed except
that containers have been getting much more press than they deserve (IMHO).
Container security just isn't to a point that I'd trust outside a safe, test,
network for trusted people.  Perhaps in another 5 yrs, Docker, LXC, LXD will be
mature enough to trust on the internet - I dunno. No amount of claims about
security can replace years of ACTUALLY BEING secure.


IMHO.



On 01/10/2016 01:43 AM, Steve Litt wrote:
> On Sat, 9 Jan 2016 14:29:32 -0800
> Alex Carver <agcarver+ale at acarver.net> wrote:
> 
>> I'm playing with VMs on a home Win 7 computer so I can practice using
>> the same setup with a work Win 7 computer (the idea being to run Linux
>> in the VM for certain tasks).
>>
>> Right now I've started using VirtualBox but it seems a bit slower
>> than I expected (I know it's going to be slower than bare metal).  Any
>> suggestions for improving the speed/efficiency of the VM?
> 
> My setup is different from yours, but I'll tell you what I've seen.
> 
> Keep in mind that my host is Linux, and my guests are Linux.
> 
> Just before leaving Debian Wheezy for Void, I was using Virtualbox. It
> was nice, but it frequently aborted without warning or error message
> while doing big installs like Gentoo. I switched to Qemu, and it was
> rock solid.
> 
> My experience with Qemu (and as I remember with Virtualbox) was that
> they were noticably faster than bare metal. This is subjective, but I'm
> pretty sure true.
> 
> I've always made my guest systems as simple as possible.
> 
>>
>> The test machine is a Core i7 with 16 GB RAM so I've given the VM 4 GB
>> of RAM.  
> 
> Yes, that's what I do.
> 
>> The installation process for the guest Linux is exceptionally
>> slow, though, which is why I suspect I've set something up wrong or
>> maybe VirtualBox isn't the best choice?
> 
> If it's *exceptionally* slow, I'd start to suspect lack of hardware
> acceleration, either because your mobo/processor isn't capable of it,
> or because you didn't put the hardware acceleration whatever into
> VirtualBox (in Qemu it's -enable-kvm ).
>>
>> According to the guest machine properties, VT-x, nested paging and KVM
>> Paravirtualization are all enabled.
> 
> Ugh! That shoots down that theory.
> 
>> For the installation, I'm using this as an experimental platform to
>> learn how to install and manage LVM (and some other experiments on
>> something that I don't care if I have to wipe).  So I have one virtual
>> HDD of 20 GB split into three partitions (/boot, LVM PV, and swap),
>> the PV is part of a single VG and there's a single LV on top of that
>> VG for root.
> 
> Just for fun, why don't you lay down Lubuntu 14.04LTS in a VM, taking
> all the defaults, and see if *that's* slow. If not, you can start to
> exploit the differences.