User-mode Linux: Difference between revisions

Revision as of 14:12, 26 April 2023

Latest revision as of 04:04, 11 August 2025

(6 intermediate revisions by 5 users not shown)

Line 30:

| genre = [[Virtualization]]

| license = [[GNU General Public License]]

| website = {{URL|httphttps://user-mode-linux.sourceforge.net/}}

}}

Line 45:

| last=Landley

| date=2009-12-16

| access-date=20192023-08-2908}}</ref> One can run [[computer network|network]] services from a UML environment and remain totally sequestered from the main Linux system in which the UML environment runs.<ref>{{cite web

| url=https://web.dit.upm.es/vnumlwiki/

| title=Virtual Network User-Mode-Linux

| date=2012-02-13

| access-date=20192023-08-2908}}</ref><ref>{{cite web

| url=http://wiki.netkit.org/index.php/Features

| title=Netkit: Features

| date=2009-12-03

| access-date=20192023-08-2908

| archive-date=2020-05-11

| archive-url=https://web.archive.org/web/20200511195253/http://wiki.netkit.org/index.php/Features

Line 60:

| url=http://www.marionnet.org/site/?en

| title=Marionnet: a virtual network laboratory

| authorsauthor1=Jean-Vincent Loddo & |author2=Luca Saiu

| access-date=20192023-08-2908}}</ref><ref>{{cite web

| url=https://clownix.net/doc_stored/build-03-04/singlehtml/index.html

| title=Cloonix Documentation: v03-04

| date=2019-06-01

| access-date=20192023-08-2908}}</ref><ref>{{cite web

| url=https://www.cs.mcgill.ca/~anrl/gini/

| title=Welcome to GINI! A Toolkit for Constructing User-Level Micro Internets

| date=2009-09-28

| publisher=[[McGill University]]

| access-date=20192023-08-2908}}</ref> Administrators can use UML to set up [[honeypot (computing)|honeypot]]s,<ref>{{cite web

| url=httphttps://user-mode-linux.sourceforge.net/old/honeypots.html

| title=UML as a honeypot

| date=2007-07-13

| access-date=20192023-08-2908}}</ref> which allow one to test the security of one's computers or network. UML can serve to test and debug new software without adversely affecting the host system. UML can also be used for teaching and research, providing a realistic Linux networked environment with a high degree of safety.

In UML environments, host and guest kernel versions don't need to match, so it is entirely possible to test a "[[bleeding edge]]" version of Linux in User-mode on a system running a much older kernel. UML also allows kernel debugging to be performed on one machine, where other kernel debugging tools (such as [[kgdb]]) require two machines connected with a [[null modem]] cable.

Line 90:

The UML guest application (a [[Linux kernel|Linux]] binary [[Executable and Linkable Format|ELF]]) was originally available as a [[patch (computing)|patch]] for some Kernel versions above 2.2.x, and the host with any kernel version above 2.2.x supported it easily in the thread mode (i.e., non-SKAS3).

As of [[Linux kernel|Linux]] 2.6.0, it is integrated into the main [[kernel (operating system)|kernel]] source tree. A method of running a separate kernel address space (SKAS) that does not require host kernel patching has been implemented. This improves performance and security over the old Traced Thread approach, in which processes running in the UML share the same address space from the host's point of view, which leads the memory inside the UML to not be protected by the [[memory management unit]]. Unlike the current UML using SKAS, buggy or malicious software inside a UML running on a non-SKAS host could be able to read the memory space of other UML processes or even the UML kernel memory.<ref>{{CitationCite book |title=User Mode Linux |last=Dike |first=Jeff needed|date=October2006-04-12 2012|publisher=[[Prentice Hall]] |isbn=9780131865051 |pages=197}}</ref>

== Comparison with other technologies ==

Line 103:

== See also ==

* [[L4Linux]]

* [[CoLinuxcoLinux]]

* [[MkLinux]]