

User-mode Linux Kernel - grifaton
http://user-mode-linux.sourceforge.net/

======
hapless
I used to have paying customers on UML on a Red Hat 7.3 box. I had no idea
that UML had been maintained as recently as 2.6.24. I really had no reason to
follow it, because UML's niche has been eaten away from both top and bottom.

The bottom: For super-high-density virtual private servers, it makes more
sense to use OpenVZ (<http://www.openvz.org>) and its commercial counterpart,
Virtuozzo (<http://www.parallels.com>). I've seen installations with 300-500
VMs running on a system with 2G of RAM. It's not a great user experience, but
it sure is ... dense. This is where those $5/month VPSes came from.

The top: For more conventional virtualization needs, there's Xen and KVM. More
flexible, less of a pain in the system administrator's ass. This is the route
Slicehost and Linode took.

~~~
petercooper
What about for sandboxing processes? I've been investigating UML for this use
as it seems "lighter" than the other approaches you've outlined yet still
gives good network separation and reasonable control from a supervising
process. I've also been investigating AppArmor but it seems a little like
wrapping a blanket around a bomb so far.. but I'm really just walking around
in the dark so far.

~~~
justincormack
Use Linux containers (lxc). Exactly what you need...

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nwmcsween
Linux containers don't offer real separation right now, there are still data
leaks and issues such as shutdown -h within a lxc causing the host to shutdown
and many other issues. Lxc as of now is barely alpha quality.

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dgl
When there weren't so many options for Linux virtualisation this was where
Linode started out:
[http://www.linode.com/wiki/index.php/Linode#What_makes_a_Lin...](http://www.linode.com/wiki/index.php/Linode#What_makes_a_Linode_different.3F)

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otterley
Not news. UML is at least 12 years old.

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rythie
We used that for quite a few years, were able to get 40-50 VMs on a Dual-Xeon
box with 6GB of memory with no trouble. It's very lightweight and flexible
with memory compared to systems like KVM and VirtualBox

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alextp
UML brings back good memories from OS classes. We had to patch ext3 to add
some triviality, and I did it first in UML so I could more easily test and
make sure it was working correctly. It felt a lot faster and easier to setup
than virtualbox or qemu (my options at the time), although I guess with
hardware support and things like hypervisors it's no longer practical.

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pan69
Interesting. Is this similar to CouldLinux? <http://www.cloudlinux.com>

~~~
nepenthe2
Cloud Linux is marketed towards shared hosting providers, often the kind that
might have 300-2000 websites on a single server. The isolation prevents rogue
PHP scripts from taking down the entire server normally seen with non-
updated/misconfigured WordPress or common forum software.

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nzmsv
There even exists a port of UML for Windows:
<http://umlwin32.sourceforge.net/>

And that project (indirectly) led to coLinux (<http://www.colinux.org/>),
which runs on Windows at the kernel level. Linus himself called coLinux a
dirty hack!

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anonymous246
What? That's it? Flagged.

~~~
anonymous246
Dear downmodders, the submitter should have at least put the fig leaf of an
"Ask HN" sentence around this to make this interesting. Otherwise, a post to
the homepage of a 12-yr old project makes no sense and is polluting HN.

~~~
sorbus
Comments which complain about articles polluting HN and say nothing other than
that the commenter is flagging it are polluting HN, and are against the
guidelines:

"Please don't submit comments complaining that a submission is inappropriate
for the site. If you think something is spam or offtopic, flag it by going to
its page and clicking on the "flag" link. (Not all users will see this; there
is a karma threshold.) If you flag something, please don't also comment that
you did."

~~~
anonymous246
Fair enough. Noted. Thanks for replying.

