Linus Thinks Virtualization Is 'Evil'

Front page first-timer crdotson writes "Linus said in an interview that he thinks virtualization is 'evil' because he prefers to deal with the real hardware. Hardware virtualization allows for better barriers between systems by running multiple OSes on the same hardware, but OS-level virtualization allows similar barriers without a hypervisor between the kernel and the hardware. Should we expect more focus on OS-level virtualization such as Linux-VServer, OpenVZ, and LXC?"

Comments

Screws are evil

[Anonymous Coward]

Because I'm used to working with a hammer.

Linus is not a god, just a guy, with his own prejudices.

Re:Screws are evil

[timeOday]

Read the article. Linus has accepted both KVM and Xen into the kernel, it talks about why he and some other guru think KVM was managed better and is a better implementation.

Let's not confuse two completely different things: if Richard Stallman said something was "evil," it would mean he was morally opposed to it and wouldn't touch it with a 10 foot pole. But Linus calling hypervisor virtualization "evil" just means he'd rather work on hardware, but hey, you want virtualization, go ahead and take your pick of the ones Linux provides.

wrong, OS level Implementation is the problem

[g00mbasv]

The title is a bit on the FUD style. PROPER virtualization is not criticized by Linus, but improper implementation, namely cheap OS-level virtualization wich could lead to lazy shortcuts to patches and features implementation.

40+ years of experience

[stox]

If you want to see where virtualization is going, check out where VM370 was in 1977 or so. That is about as far as the current virtualization technology has gotten. Bare metal has its place, as does virtualization.

Re:Idiotic, that's what OS's do

[Jon Stone]

Virtualisation is, in many ways, trying to do what the OS should already be doing, namely isolation between processes (though protected memory), providing an abstraction layer for the hardware (though drivers) and allocating resources (through the CPU/IO schedulers).

Unfortunately, a certain OS has been so bad at doing this (historically) that people turn to virtualisation and you end up with a form of inner-platform effect. We have Linux implementing the virtio drivers to interface with the hypervisor which implements real drivers to talk to the real hardware. We have the guest's scheduler trying to manage "virtual CPUs" without any real information about what resources are actually available. We have hypervisors trying to re-implement copy-on-write for memory pages that the OS already does out-of-the-box.

Virtualisation is used as a "one size fits all" sledgehammer, often where it isn't the appropriate solution.

Linus doesn't really think it's Evil

[steveha]

Linus likes to say things that are a bit over-the-top. He trusts that his audience can detect the tongue-in-cheek nature of the comments.

I do the same thing. If I say something like "I hate and fear Perl", I don't mean it literally.

Some people were upset about Linus's presentation about Git where he bashed Subversion. I thought it was pretty clear that he was exaggerating his comments for comedic effects, and I was entertained rather than outraged.

Linus does sometimes say things I disagree with. He resisted having an official kernel debugger for years, because he said kernel developers should be able to hold everything in their heads and not need a debugger to help them. (Did he ever give in on that?) But this current issue is a non-issue.

steveha