LWN: Comments on "Qubes OS nears version 3.0"

power consumption

imitev — Thu, 04 Jun 2015 14:43:47 +0000

Thanks for the answer. My use case doesn't have any of the limitations you mentionned, so I'll give Qubes a try soon - I plan to try the R3.0 rc1 first and then revert to R2 rc2 if it's too bleeding edge.

power consumption

pendic — Thu, 04 Jun 2015 12:11:33 +0000

So, have been using Qubes on my primary laptop for more than a year now. Unfortunately I don't have numbers for "typical" laptop use as I normally have dozens of applications running. That said, I feel comfortable that I can get serious work done without having to worry about the battery. I would recommend that you simply try it on the laptop you want to use it on for a couple of days as it's worth the time investment.

So far I'm quite happy with it (and was pretty surprised at how usable Qubes is out of the box). Limitations that might be a deal breaker for your scenario:

- Can't really play an HD movie full screen (this is, AFAIU, a fundamental limitation of how display is being done)
- While USB mass storage and input devices fit well into the current Qubes architecture, you cannot ATM forward other USB devices to arbitrary VMs. So if you regularly plug in e.g. a USB wireless card, your best bet would be to do PCI passthrough for the USB hub. Which, on a laptop, would probably mean that all your USB ports need to be assigned to this specific VM.
- 4GB of RAM should be plenty for emails and browsing. If you have less, that might be an issue (assuming that you actually /use/ different protection domains).
- Multi-user is not supported, so take that into account if you're occasionally sharing the laptop with someone else.

Running it in a VM not supported

robbe — Wed, 03 Jun 2015 20:57:28 +0000

As others have commented, nesting hypervisors is possible, so I'd be interested in why Qubes would not work. Maybe missing VT-d support is an issue?

power consumption

imitev — Sun, 31 May 2015 18:29:19 +0000

I'm contemplating trying Qubes OS for a while now, but I'm wondering what would be the overhead of running stuff in vms in term of power consumption for a typical laptop use (browsing, emails, ...).

A quick web search didn't provide meaningful results, it'll be interesting to hear about fellow LWN readers who tried Qubes OS.

Running it in a VM not supported

pwfxq — Sun, 31 May 2015 05:31:13 +0000

You can nest hypervisors - it's how training companies run VMware courses. VMWare has a document on nesting their products and running other hypervisors under VMWare: communities.vmware.com/docs/DOC-8970.

I recall seeing somewhere that you could nest ESXi inside ESXi inside ESXi but you couldn't go any further - so it's not turtles all the way down ;-)

Running it in a VM not supported

ibukanov — Fri, 29 May 2015 09:08:51 +0000

It is possible to run nested hypervisors on x86. The issue is if one can do it with reasonable performance. For example, running KVM under VMWare is OK. Perhaps for XEN the picture is not so bright and not all the features required by Qubes is supported.

Running it in a VM not supported

epa — Fri, 29 May 2015 07:06:15 +0000

Ah, this OS cannot itself be run in a virtual machine. So x86 and x86-64 systems are still not fully virtualizable - only part of the processor's functions can be used in a VM. Rather like the old V86 mode which provided a virtual 16-bit system on 32-bit machines like the 386, but could not itself run 32-bit code.

I suppose then we will inevitably see meta-virtualization, so operating systems like Qubes can be run in a VM, and that will be fine until such point as meta-virtualization itself starts to be used in building an operating environment...

What about the mainframe systems that provide virtual machines? Will they allow VMs inside VMs?