SherbyNet - /page/wikibook/entry.mu

Micron Document

<!DOCTYPE html>

<title>Linux Virtual Server</title>

</head>

<span id="openzim-page-title" class="mw-page-title-main"><span class="mw-page-title-main">Linux Virtual Server</span></span>

</h1>

</header>

/* start https://en.wikipedia.org/ */

.mw-parser-output .infobox-subbox{padding:0;border:none;margin:-3px;width:auto;min-width:100%;font-size:100%;clear:none;float:none;background-color:transparent}.mw-parser-output .infobox-3cols-child{margin:auto}.mw-parser-output .infobox .navbar{font-size:100%}@media screen{html.skin-theme-clientpref-night .mw-parser-output .infobox-full-data:not(.notheme)>div:not(.notheme)[style]{background:#1f1f23!important;color:#f8f9fa}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .infobox-full-data:not(.notheme)>div:not(.notheme)[style]{background:#1f1f23!important;color:#f8f9fa}}@media(min-width:640px){body.skin--responsive .mw-parser-output .infobox-table{display:table!important}body.skin--responsive .mw-parser-output .infobox-table>caption{display:table-caption!important}body.skin--responsive .mw-parser-output .infobox-table>tbody{display:table-row-group}body.skin--responsive .mw-parser-output .infobox-table th,body.skin--responsive .mw-parser-output .infobox-table td{padding-left:inherit;padding-right:inherit}}

/* end https://en.wikipedia.org/ */

</style><table class="infobox vevent"><tbody><tr><td colspan="2" class="infobox-image logo"><span typeof="mw:File"></span><div class="infobox-caption">LVS official logo</div></td></tr><tr><th scope="row" class="infobox-label" style="white-space: nowrap;"><a href="Programmer" title="Programmer">Original author(s)</a></th><td class="infobox-data">Wensong Zhang</td></tr><tr><th scope="row" class="infobox-label" style="white-space: nowrap;"><a href="Programmer" title="Programmer">Developer(s)</a></th><td class="infobox-data">et al.</td></tr><tr><th scope="row" class="infobox-label" style="white-space: nowrap;">Initial release</th><td class="infobox-data">May 1998<span style="display:none"> (<span class="bday dtstart published updated">1998-05</span>)</span></td></tr><tr><th scope="row" class="infobox-label" style="white-space: nowrap;">Written in</th><td class="infobox-data"><a href="C_(programming_language)" title="C (programming language)">C</a></td></tr><tr><th scope="row" class="infobox-label" style="white-space: nowrap;"><a href="Operating_system" title="Operating system">Operating system</a></th><td class="infobox-data"><a href="Linux" title="Linux">Linux</a></td></tr><tr><th scope="row" class="infobox-label" style="white-space: nowrap;"><a href="Software_categories#Categorization_approaches" title="Software categories">Type</a></th><td class="infobox-data"><a href="Load_balancing_(computing)" title="Load balancing (computing)">load balancing</a></td></tr><tr><th scope="row" class="infobox-label" style="white-space: nowrap;"><a href="Software_license" title="Software license">License</a></th><td class="infobox-data"><a href="GNU_General_Public_License" title="GNU General Public License">GNU General Public License</a></td></tr><tr><th scope="row" class="infobox-label" style="white-space: nowrap;">Website</th><td class="infobox-data"><span class="url"><a rel="nofollow" class="external text" href="http://www.LinuxVirtualServer.org">www<wbr>.linuxvirtualserver<wbr>.org</a></span></td></tr></tbody></table>

<p><b>Linux Virtual Server</b> (<b>LVS</b>) is <a href="Load_balancing_(computing)" title="Load balancing (computing)">load balancing</a> software for <a href="Linux_kernel" title="Linux kernel">Linux kernel</a>–based operating systems.

</p><p>LVS is a <a href="Free_and_open-source" class="mw-redirect" title="Free and open-source">free and open-source</a> project started by Wensong Zhang in May 1998, subject to the requirements of the <a href="GNU_General_Public_License" title="GNU General Public License">GNU General Public License</a> (GPL), version 2. The mission of the project is to build a high-performance and highly available server for Linux using <a href="Computer_cluster" title="Computer cluster">clustering</a> technology, which provides good scalability, reliability and serviceability.

</p>

<div class="mw-heading mw-heading2"><h2 id="Overview">Overview</h2></div>

<p>The major work of the LVS project is now to develop advanced IP <a href="Load_balancing_(computing)" title="Load balancing (computing)">load balancing</a> software (IPVS), application-level load balancing software (KTCPVS), and cluster management components.

</p>

<ul><li><a href="IP_Virtual_Server" title="IP Virtual Server">IPVS</a>: an advanced IP load balancing software implemented inside the <a href="Linux_kernel" title="Linux kernel">Linux kernel</a>. The <a href="IP_Virtual_Server" title="IP Virtual Server">IP Virtual Server</a> code is merged into versions 2.4.x and newer of the Linux kernel mainline.<sup id="cite_ref-1" class="reference"><a href="#cite_note-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup></li>

<li>KTCPVS: implements application-level load balancing inside the Linux kernel, as of February 2011 still under development.<sup id="cite_ref-2" class="reference"><a href="#cite_note-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup></li></ul>

<p>LVS can be used for building highly scalable and <a href="High-availability_cluster" title="High-availability cluster">highly available</a> network services, such as web, email, media and <a href="VoIP" class="mw-redirect" title="VoIP">VoIP</a> services, and integrating scalable network services into large-scale reliable <a href="E-commerce" title="E-commerce">e-commerce</a> or <a href="E-government" title="E-government">e-government</a> applications. LVS-based solutions already have been deployed in many real applications throughout the world, including <a href="Wikipedia" title="Wikipedia">Wikipedia</a>.

</p><p>The LVS components depend upon the Linux <a href="Netfilter" title="Netfilter">Netfilter</a> framework, and its source code is available in the <code>net/netfilter/ipvs</code> subdirectory within the <a href="Linux_kernel" title="Linux kernel">Linux kernel</a> source. LVS is able to handle UDP, TCP layer-4 protocols as well as FTP passive connection by inspecting layer-7 packets. It provides a hierarchy of counters in the <code>/proc</code> directory.

</p><p>The <a href="Userland_(computing)" class="mw-redirect" title="Userland (computing)">userland</a> utility program used to configure LVS is called <a href="Ipvsadm" class="mw-redirect" title="Ipvsadm">ipvsadm</a>, which requires <a href="Superuser" title="Superuser">superuser</a> privileges to run.

</p>

<div class="mw-heading mw-heading3"><h3 id="Schedulers">Schedulers</h3></div>

<p>LVS implements several balancing schedulers, listed below with the relevant source files:<sup id="cite_ref-3" class="reference"><a href="#cite_note-3"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup>

</p>

<ul><li>Round-robin (<code>ip_vs_rr.c</code>)</li>

<li>Weighted round-robin (<code>ip_vs_wrr.c</code>)</li>

<li>Least-connection (<code>ip_vs_lc.c</code>)</li>

<li>Weighted least-connection (<code>ip_vs_wlc.c</code>)</li>

<li>Locality-based least-connection (<code>ip_vs_lblc.c</code>)</li>

<li>Locality-based least-connection with replication (<code>ip_vs_lblcr.c</code>)</li>

<li>Destination hashing (<code>ip_vs_dh.c</code>)</li>

<li>Source hashing (<code>ip_vs_sh.c</code>)</li>

<li>Shortest expected delay (<code>ip_vs_sed.c</code>)</li>

<li>Never queue (<code>ip_vs_nq.c</code>)</li>

<li>Maglev hashing (<code>ip_vs_mh.c</code>)</li></ul>

<div class="mw-heading mw-heading2"><h2 id="Glossary">Glossary</h2></div>

<p>Commonly used terms include the following:<sup id="cite_ref-Bob_4-0" class="reference"><a href="#cite_note-Bob-4"><span class="cite-bracket">[</span>4<span class="cite-bracket">]</span></a></sup>

</p>

<ul><li><i>LVS director</i>: load balancer that receives all incoming client requests for services and directs them to a specific "real server" to handle the request</li>

<li><i>Real servers</i>: nodes that make up an LVS cluster which are used to provide services on the behalf of the cluster</li>

<li><i>Client computers</i>: computers requesting services from the virtual server</li>

<li><i>VIP (Virtual IP address)</i>: the IP address used by the director to provide services to client computers</li>

<li><i>RIP (Real IP address)</i>: the IP address used to connect to the cluster nodes</li>

<li><i>DIP (Directors IP address)</i>: the IP address used by the director to connect to network of real IP addresses</li>

<li><i>CIP (Client IP address)</i>: the IP address assigned to a client computer, that it uses as the source IP address for requests being sent to the cluster</li></ul>

<div class="mw-heading mw-heading2"><h2 id="Examples">Examples</h2></div>

<p>Setting up a virtual <a href="Hypertext_Transfer_Protocol" class="mw-redirect" title="Hypertext Transfer Protocol">HTTP</a> server with two real servers:

</p>

<div class="mw-highlight mw-highlight-lang-bash mw-content-ltr" dir="ltr"><pre>ipvsadm<span class="w"> </span>-A<span class="w"> </span>-t<span class="w"> </span><span class="m">192</span>.168.0.1:80<span class="w"> </span>-s<span class="w"> </span>rr

ipvsadm<span class="w"> </span>-a<span class="w"> </span>-t<span class="w"> </span><span class="m">192</span>.168.0.1:80<span class="w"> </span>-r<span class="w"> </span><span class="m">172</span>.16.0.1:80<span class="w"> </span>-m

</pre></div>

<p>The first command assigns <a href="Transmission_Control_Protocol" title="Transmission Control Protocol">TCP</a> port 80 on <a href="IP_address" title="IP address">IP address</a> <a href="Private_network" title="Private network">192.168.0.1</a> to the virtual server. The chosen scheduling algorithm for <a href="Load_balancing_(computing)" title="Load balancing (computing)">load balancing</a> is <a href="Round-robin_scheduling" title="Round-robin scheduling">round-robin</a> (<code>-s rr</code>). The second and third commands are adding IP addresses of real servers to the LVS setup. The forwarded network packets shall be masked (<code>-m</code>).<sup id="cite_ref-5" class="reference"><a href="#cite_note-5"><span class="cite-bracket">[</span>5<span class="cite-bracket">]</span></a></sup>

</p><p>Querying the status of the above configured LVS setup:

</p>

<div class="mw-highlight mw-highlight-lang-text mw-content-ltr" dir="ltr"><pre># ipvsadm -L -n

IP Virtual Server version 1.0.8 (size=65536)

Prot LocalAddress:Port Scheduler Flags

-> RemoteAddress:Port Forward Weight ActiveConn InActConn

TCP 192.168.0.1:80 rr

-> 172.16.0.2:80 Masq 1 3 1

-> 172.16.0.1:80 Masq 1 4 0

</pre></div>

/* start https://en.wikipedia.org/ */

.mw-parser-output .portalbox{padding:0;margin:0.5em 0;display:table;box-sizing:border-box;max-width:175px;list-style:none}.mw-parser-output .portalborder{border:1px solid var(--border-color-base,#a2a9b1);padding:0.1em;background:var(--background-color-neutral-subtle,#f8f9fa)}.mw-parser-output .portalbox-entry{display:table-row;font-size:85%;line-height:110%;height:1.9em;font-style:italic;font-weight:bold}.mw-parser-output .portalbox-image{display:table-cell;padding:0.2em;vertical-align:middle;text-align:center}.mw-parser-output .portalbox-link{display:table-cell;padding:0.2em 0.2em 0.2em 0.3em;vertical-align:middle}@media(min-width:720px){.mw-parser-output .portalleft{margin:0.5em 1em 0.5em 0}.mw-parser-output .portalright{clear:right;float:right;margin:0.5em 0 0.5em 1em}}

/* end https://en.wikipedia.org/ */

</style>

<ul><li><a href="IP_Virtual_Server" title="IP Virtual Server">IP Virtual Server</a></li>

<li><a href="Netfilter" title="Netfilter">Netfilter</a> and <a href="Nftables" title="Nftables">nftables</a></li>

<li><a href="Network_scheduler" title="Network scheduler">Network scheduler</a></li></ul>

<div class="mw-heading mw-heading2"><h2 id="References">References</h2></div>

/* start https://en.wikipedia.org/ */

.mw-parser-output .reflist{margin-bottom:0.5em;list-style-type:decimal}@media screen{.mw-parser-output .reflist{font-size:90%}}.mw-parser-output .reflist .references{font-size:100%;margin-bottom:0;list-style-type:inherit}.mw-parser-output .reflist-columns-2{column-width:30em}.mw-parser-output .reflist-columns-3{column-width:25em}.mw-parser-output .reflist-columns{margin-top:0.3em}.mw-parser-output .reflist-columns ol{margin-top:0}.mw-parser-output .reflist-columns li{page-break-inside:avoid;break-inside:avoid-column}.mw-parser-output .reflist-upper-alpha{list-style-type:upper-alpha}.mw-parser-output .reflist-upper-roman{list-style-type:upper-roman}.mw-parser-output .reflist-lower-alpha{list-style-type:lower-alpha}.mw-parser-output .reflist-lower-greek{list-style-type:lower-greek}.mw-parser-output .reflist-lower-roman{list-style-type:lower-roman}

/* end https://en.wikipedia.org/ */

</style><div class="reflist">

/* start https://en.wikipedia.org/ */

.mw-parser-output cite.citation{font-style:inherit;word-wrap:break-word}.mw-parser-output .citation q{quotes:"\"""\"""'""'"}.mw-parser-output .citation:target{background-color:rgba(0,127,255,0.133)}.mw-parser-output .id-lock-free.id-lock-free a{background:url("./mw/Lock-green.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-limited.id-lock-limited a,.mw-parser-output .id-lock-registration.id-lock-registration a{background:url("./mw/Lock-gray-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-subscription.id-lock-subscription a{background:url("./mw/Lock-red-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .cs1-ws-icon a{background:url("./mw/Wikisource-logo.svg")right 0.1em center/12px no-repeat}body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-free a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-limited a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-registration a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-subscription a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .cs1-ws-icon a{background-size:contain;padding:0 1em 0 0}.mw-parser-output .cs1-code{color:inherit;background:inherit;border:none;padding:inherit}.mw-parser-output .cs1-hidden-error{display:none;color:var(--color-error,#d33)}.mw-parser-output .cs1-visible-error{color:var(--color-error,#d33)}.mw-parser-output .cs1-maint{display:none;color:#085;margin-left:0.3em}.mw-parser-output .cs1-kern-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right{padding-right:0.2em}.mw-parser-output .citation .mw-selflink{font-weight:inherit}@media screen{.mw-parser-output .cs1-format{font-size:95%}html.skin-theme-clientpref-night .mw-parser-output .cs1-maint{color:#18911f}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .cs1-maint{color:#18911f}}

/* end https://en.wikipedia.org/ */

</style><cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://www.linuxvirtualserver.org/software/ipvs.html">"IPVS Software - Advanced Layer-4 Switching"</a>. linuxvirtualserver.org. 2011-02-08<span class="reference-accessdate">. Retrieved <span class="nowrap">2014-01-12</span></span>.</cite></span>

</li>

<li id="cite_note-2"><span class="mw-cite-backlink"><b><a href="#cite_ref-2">^</a></b></span> <span class="reference-text"><cite id="CITEREFWensong_Zhang2011" class="citation web cs1">Wensong Zhang (2011-02-08). <a rel="nofollow" class="external text" href="http://www.linuxvirtualserver.org/software/ktcpvs/ktcpvs.html">"KTCPVS Software - Application-Level Load Balancing"</a>. Linuxvirtualserver.org<span class="reference-accessdate">. Retrieved <span class="nowrap">2014-03-25</span></span>.</cite></span>

</li>

<li id="cite_note-3"><span class="mw-cite-backlink"><b><a href="#cite_ref-3">^</a></b></span> <span class="reference-text"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://www.linuxvirtualserver.org/docs/scheduling.html">"Job Scheduling Algorithms in Linux Virtual Server"</a>. linuxvirtualserver.org. 2011-02-08<span class="reference-accessdate">. Retrieved <span class="nowrap">2013-11-24</span></span>.</cite></span>

</li>

<li id="cite_note-Bob-4"><span class="mw-cite-backlink"><b><a href="#cite_ref-Bob_4-0">^</a></b></span> <span class="reference-text"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://bobcares.com/blog/linux-virtual-server-load-balance-your-networked-services/">"Linux Virtual Server: Load Balance Your Networked Services"</a>. bobcares.com. 2008<span class="reference-accessdate">. Retrieved <span class="nowrap">2013-11-24</span></span>.</cite></span>

</li>

<li id="cite_note-5"><span class="mw-cite-backlink"><b><a href="#cite_ref-5">^</a></b></span> <span class="reference-text"><cite id="CITEREFPeter" class="citation news cs1">Peter, Jeff. <a rel="nofollow" class="external text" href="https://xaro.net/blog/understanding-vps-vs-vds-guide/">"Understanding Virtual Server"</a><span class="reference-accessdate">. Retrieved <span class="nowrap">18 June</span> 2023</span>.</cite></span>

</li>

</ol></div></div>

<div class="mw-heading mw-heading2"><h2 id="External_links">External links</h2></div>

<ul><li><span class="official-website"><span class="url"><a rel="nofollow" class="external text" href="http://www.LinuxVirtualServer.org/">Official website</a></span></span></li>

<li><a rel="nofollow" class="external text" href="http://kb.linuxvirtualserver.org/wiki/Main_Page">Linux Virtual Server Configuration Wiki</a></li>

<li><a rel="nofollow" class="external text" href="http://publib-b.boulder.ibm.com/Redbooks.nsf/9445fa5b416f6e32852569ae006bb65f/e8417f0abc3cadaf85256d40004f31b8?OpenDocument&Highlight=0,SG247034">IBM eServer BladeCenter, Linux, and Open Source: Blueprint for e-business on demand</a> <a rel="nofollow" class="external text" href="https://web.archive.org/web/20220811174534/https://publib-b.boulder.ibm.com/Redbooks.nsf/9445fa5b416f6e32852569ae006bb65f/e8417f0abc3cadaf85256d40004f31b8?OpenDocument&Highlight=0,SG247034">Archived</a> 2022-08-11 at the <a href="Wayback_Machine" title="Wayback Machine">Wayback Machine</a> (includes LVS as a component)</li></ul>

/* start https://en.wikipedia.org/ */

.mw-parser-output .hlist dl,.mw-parser-output .hlist ol,.mw-parser-output .hlist ul{margin:0;padding:0}.mw-parser-output .hlist dd,.mw-parser-output .hlist dt,.mw-parser-output .hlist li{margin:0;display:inline}.mw-parser-output .hlist.inline,.mw-parser-output .hlist.inline dl,.mw-parser-output .hlist.inline ol,.mw-parser-output .hlist.inline ul,.mw-parser-output .hlist dl dl,.mw-parser-output .hlist dl ol,.mw-parser-output .hlist dl ul,.mw-parser-output .hlist ol dl,.mw-parser-output .hlist ol ol,.mw-parser-output .hlist ol ul,.mw-parser-output .hlist ul dl,.mw-parser-output .hlist ul ol,.mw-parser-output .hlist ul ul{display:inline}.mw-parser-output .hlist .mw-empty-li{display:none}.mw-parser-output .hlist dt::after{content:": "}.mw-parser-output .hlist dd::after,.mw-parser-output .hlist li::after{content:" · ";font-weight:bold}.mw-parser-output .hlist dd:last-child::after,.mw-parser-output .hlist dt:last-child::after,.mw-parser-output .hlist li:last-child::after{content:none}.mw-parser-output .hlist dd dd:first-child::before,.mw-parser-output .hlist dd dt:first-child::before,.mw-parser-output .hlist dd li:first-child::before,.mw-parser-output .hlist dt dd:first-child::before,.mw-parser-output .hlist dt dt:first-child::before,.mw-parser-output .hlist dt li:first-child::before,.mw-parser-output .hlist li dd:first-child::before,.mw-parser-output .hlist li dt:first-child::before,.mw-parser-output .hlist li li:first-child::before{content:" (";font-weight:normal}.mw-parser-output .hlist dd dd:last-child::after,.mw-parser-output .hlist dd dt:last-child::after,.mw-parser-output .hlist dd li:last-child::after,.mw-parser-output .hlist dt dd:last-child::after,.mw-parser-output .hlist dt dt:last-child::after,.mw-parser-output .hlist dt li:last-child::after,.mw-parser-output .hlist li dd:last-child::after,.mw-parser-output .hlist li dt:last-child::after,.mw-parser-output .hlist li li:last-child::after{content:")";font-weight:normal}.mw-parser-output .hlist ol{counter-reset:listitem}.mw-parser-output .hlist ol>li{counter-increment:listitem}.mw-parser-output .hlist ol>li::before{content:" "counter(listitem)"\a0 "}.mw-parser-output .hlist dd ol>li:first-child::before,.mw-parser-output .hlist dt ol>li:first-child::before,.mw-parser-output .hlist li ol>li:first-child::before{content:" ("counter(listitem)"\a0 "}

/* end https://en.wikipedia.org/ */

</style><style data-mw-deduplicate="TemplateStyles:r1236075235">

/* start https://en.wikipedia.org/ */

.mw-parser-output .navbox{box-sizing:border-box;border:1px solid #a2a9b1;width:100%;clear:both;font-size:88%;text-align:center;padding:1px;margin:1em auto 0}.mw-parser-output .navbox .navbox{margin-top:0}.mw-parser-output .navbox+.navbox,.mw-parser-output .navbox+.navbox-styles+.navbox{margin-top:-1px}.mw-parser-output .navbox-inner,.mw-parser-output .navbox-subgroup{width:100%}.mw-parser-output .navbox-group,.mw-parser-output .navbox-title,.mw-parser-output .navbox-abovebelow{padding:0.25em 1em;line-height:1.5em;text-align:center}.mw-parser-output .navbox-group{white-space:nowrap;text-align:right}.mw-parser-output .navbox,.mw-parser-output .navbox-subgroup{background-color:#fdfdfd}.mw-parser-output .navbox-list{line-height:1.5em;border-color:#fdfdfd}.mw-parser-output .navbox-list-with-group{text-align:left;border-left-width:2px;border-left-style:solid}.mw-parser-output tr+tr>.navbox-abovebelow,.mw-parser-output tr+tr>.navbox-group,.mw-parser-output tr+tr>.navbox-image,.mw-parser-output tr+tr>.navbox-list{border-top:2px solid #fdfdfd}.mw-parser-output .navbox-title{background-color:#ccf}.mw-parser-output .navbox-abovebelow,.mw-parser-output .navbox-group,.mw-parser-output .navbox-subgroup .navbox-title{background-color:#ddf}.mw-parser-output .navbox-subgroup .navbox-group,.mw-parser-output .navbox-subgroup .navbox-abovebelow{background-color:#e6e6ff}.mw-parser-output .navbox-even{background-color:#f7f7f7}.mw-parser-output .navbox-odd{background-color:transparent}.mw-parser-output .navbox .hlist td dl,.mw-parser-output .navbox .hlist td ol,.mw-parser-output .navbox .hlist td ul,.mw-parser-output .navbox td.hlist dl,.mw-parser-output .navbox td.hlist ol,.mw-parser-output .navbox td.hlist ul{padding:0.125em 0}.mw-parser-output .navbox .navbar{display:block;font-size:100%}.mw-parser-output .navbox-title .navbar{float:left;text-align:left;margin-right:0.5em}body.skin--responsive .mw-parser-output .navbox-image img{max-width:none!important}@media print{body.ns-0 .mw-parser-output .navbox{display:none!important}}

/* end https://en.wikipedia.org/ */

</style></div><div role="navigation" class="navbox" aria-labelledby="Linux_kernel514" style="padding:3px"><table class="nowraplinks hlist mw-collapsible autocollapse navbox-inner" style="border-spacing:0;background:transparent;color:inherit"><tbody><tr><th scope="col" class="navbox-title" colspan="2"><style data-mw-deduplicate="TemplateStyles:r1239400231">

/* start https://en.wikipedia.org/ */

.mw-parser-output .navbar{display:inline;font-size:88%;font-weight:normal}.mw-parser-output .navbar-collapse{float:left;text-align:left}.mw-parser-output .navbar-boxtext{word-spacing:0}.mw-parser-output .navbar ul{display:inline-block;white-space:nowrap;line-height:inherit}.mw-parser-output .navbar-brackets::before{margin-right:-0.125em;content:"[ "}.mw-parser-output .navbar-brackets::after{margin-left:-0.125em;content:" ]"}.mw-parser-output .navbar li{word-spacing:-0.125em}.mw-parser-output .navbar a>span,.mw-parser-output .navbar a>abbr{text-decoration:inherit}.mw-parser-output .navbar-mini abbr{font-variant:small-caps;border-bottom:none;text-decoration:none;cursor:inherit}.mw-parser-output .navbar-ct-full{font-size:114%;margin:0 7em}.mw-parser-output .navbar-ct-mini{font-size:114%;margin:0 4em}html.skin-theme-clientpref-night .mw-parser-output .navbar li a abbr{color:var(--color-base)!important}@media(prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .navbar li a abbr{color:var(--color-base)!important}}@media print{.mw-parser-output .navbar{display:none!important}}

/* end https://en.wikipedia.org/ */

</style><div id="Linux_kernel514" style="font-size:114%;margin:0 4em"><a href="Linux_kernel" title="Linux kernel">Linux kernel</a></div></th></tr><tr><th scope="row" class="navbox-group" style="width:1%">Organization</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th id="Kernel19" scope="row" class="navbox-group" style="width:1%">Kernel</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em">

<ul><li><a href="Linux_Foundation" title="Linux Foundation">Linux Foundation</a></li>

<li><a href="Linux_Mark_Institute" title="Linux Mark Institute">Linux Mark Institute</a></li>

<li><a href="Linus's_law" title="Linus's law">Linus's law</a></li>

<li><a href="Tanenbaum%E2%80%93Torvalds_debate" title="Tanenbaum–Torvalds debate">Tanenbaum–Torvalds debate</a></li>

<li><a href="SCO%E2%80%93Linux_disputes" title="SCO–Linux disputes">SCO disputes</a></li>

<li><a href="Linaro" title="Linaro">Linaro</a></li>

<li><a href="Menuconfig" title="Menuconfig">menuconfig</a></li>

<li><a href="List_of_Linux-supported_computer_architectures" title="List of Linux-supported computer architectures">Supported computer architectures</a></li>

<li><a href="Linux_kernel_version_history" title="Linux kernel version history">Version history</a></li>

<li><a href="Criticism_of_Linux" title="Criticism of Linux">Criticism</a></li></ul>

</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Support</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em">

<ul><li>Developers

<ul><li><i><a href="The_Linux_Programming_Interface" title="The Linux Programming Interface">The Linux Programming Interface</a></i></li>

<li><a href="Kernel.org" title="Kernel.org">kernel.org</a></li>

<li><a href="Linux_conference" class="mw-redirect" title="Linux conference">Linux conferences</a></li></ul></li>

<li>Users

<ul><li><a href="Linux_user_group" title="Linux user group">Linux User Group (LUG)</a></li></ul></li></ul>

</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">People</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em">

<ul><li><a href="Werner_Almesberger" title="Werner Almesberger">Werner Almesberger</a></li>

<li><a href="H._Peter_Anvin" title="H. Peter Anvin">H. Peter Anvin</a></li>

<li><a href="Jens_Axboe" title="Jens Axboe">Jens Axboe</a></li>

<li><a href="Moshe_Bar_(investor)" title="Moshe Bar (investor)">Moshe Bar</a></li>

<li><a href="Suparna_Bhattacharya" title="Suparna Bhattacharya">Suparna Bhattacharya</a></li>

<li><a href="Andries_Brouwer" title="Andries Brouwer">Andries Brouwer</a></li>

<li><a href="Matthew_Garrett" title="Matthew Garrett">Matthew Garrett</a></li>

<li><a href="Avi_Kivity" title="Avi Kivity">Avi Kivity</a></li>

<li><a href="Con_Kolivas" title="Con Kolivas">Con Kolivas</a></li>

<li><a href="Greg_Kroah-Hartman" title="Greg Kroah-Hartman">Greg Kroah-Hartman</a></li>

<li><a href="Benson_Leung" title="Benson Leung">Benson Leung</a></li>

<li><a href="Robert_Love" title="Robert Love">Robert Love</a></li>

<li><a href="David_S._Miller" title="David S. Miller">David S. Miller</a></li>

<li><a href="Ingo_Moln%C3%A1r" title="Ingo Molnár">Ingo Molnár</a></li>

<li><a href="Andrew_Morton_(computer_programmer)" title="Andrew Morton (computer programmer)">Andrew Morton</a></li>

<li><a href="Hans_Reiser" title="Hans Reiser">Hans Reiser</a></li>

<li><a href="Rusty_Russell" title="Rusty Russell">Rusty Russell</a></li>

<li><a href="Shuah_Khan" title="Shuah Khan">Shuah Khan</a></li>

<li><a href="Linus_Torvalds" title="Linus Torvalds">Linus Torvalds</a></li>

<li><a href="Theodore_Ts'o" title="Theodore Ts'o">Theodore Ts'o</a></li>

<li><a href="Stephen_Tweedie" title="Stephen Tweedie">Stephen Tweedie</a></li>

<li><a href="Harald_Welte" title="Harald Welte">Harald Welte</a></li>

<li><a href="Chris_Wright_(programmer)" title="Chris Wright (programmer)">Chris Wright</a></li></ul>

</div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Technical</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:1%">Debugging</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em">

<li><a href="Ftrace" title="Ftrace">ftrace</a></li>

<li><a href="Kdump_(Linux)" title="Kdump (Linux)">kdump</a></li>

<li><a href="Linux_kernel_oops" title="Linux kernel oops">Linux kernel oops</a></li>

<li><a href="SystemTap" title="SystemTap">SystemTap</a></li>

</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="Booting_process_of_Linux" title="Booting process of Linux">Startup</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em">

<ul><li><a href="Vmlinux" title="Vmlinux">vmlinux</a></li>

<li><a href="System.map" title="System.map">System.map</a></li>

<li><a href="Dracut_(software)" title="Dracut (software)">dracut</a></li>

<li><a href="Initrd" class="mw-redirect" title="Initrd">initrd</a></li>

<li><a href="Initramfs" class="mw-redirect" title="Initramfs">initramfs</a></li></ul>

</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="Linux_kernel_interfaces" title="Linux kernel interfaces">ABIs</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em">

<ul><li><a href="Linux_Standard_Base" title="Linux Standard Base">Linux Standard Base</a></li>

</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="Linux_kernel_interfaces" title="Linux kernel interfaces">APIs</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:1%">Kernel</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:1%"><a href="Linux_kernel_interfaces#SCI" title="Linux kernel interfaces">System Call<br>Interface</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em">

<ul><li><a href="POSIX" title="POSIX">POSIX</a>

<ul><li><a href="Ioctl" title="Ioctl">ioctl</a></li>

<li><a href="Select_(Unix)" title="Select (Unix)">select</a></li>

<li><a href="Close_(system_call)" title="Close (system call)">close</a></li>

<li><a href="Linux_kernel_interfaces#Additions_to_POSIX" title="Linux kernel interfaces">Linux-only</a>

<ul><li><a href="Futex" title="Futex">futex</a></li>

<li><a href="Epoll" title="Epoll">epoll</a></li>

<li><a href="Splice_(system_call)" title="Splice (system call)">splice</a></li>

<li><a href="Dnotify" title="Dnotify">dnotify</a></li>

<li><a href="Inotify" title="Inotify">inotify</a></li>

<li><a href="Readahead" title="Readahead">readahead</a></li>

</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="Linux_kernel_interfaces#In–kernel_APIs" title="Linux kernel interfaces">In-kernel</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em">

<li><a href="Crypto_API_(Linux)" title="Crypto API (Linux)">Crypto API</a></li>

<li><a href="Io_uring" title="Io uring">io uring</a></li>

<li><a href="Kernfs_(Linux)" title="Kernfs (Linux)">kernfs</a></li>

<li><a href="Memory_barrier" title="Memory barrier">Memory barrier</a></li>

<li><a href="Video4Linux" title="Video4Linux">Video4Linux</a></li>

</div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="User_space_and_kernel_space" title="User space and kernel space">Userspace</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:1%"><a href="Daemon_(computing)" title="Daemon (computing)">Daemons</a>,<br><a href="Virtual_file_system" title="Virtual file system">File systems</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em">

<ul><li>bpffs</li>

<li><a href="Configfs" title="Configfs">configfs</a></li>

<li><a href="Devfs" class="mw-redirect" title="Devfs">devfs</a></li>

<li><a href="Devpts" title="Devpts">devpts</a></li>

<li><a href="Debugfs" title="Debugfs">debugfs</a></li>

<li>hugetlbfs</li>

<li>pipefs</li>

<li><a href="Procfs" title="Procfs">procfs</a></li>

<li>securityfs</li>

<li>sockfs</li>

<li><a href="Sysfs" title="Sysfs">sysfs</a></li>

<li><a href="Tmpfs" title="Tmpfs">tmpfs</a></li>

<li><a href="Systemd" title="Systemd">systemd</a>

<li><a href="Kmscon" title="Kmscon">Kmscon</a></li>

<li><a href="Binfmt_misc" title="Binfmt misc">binfmt_misc</a></li></ul>

</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="Wrapper_library" title="Wrapper library">Wrapper<br>libraries</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em">

<ul><li><a href="C_standard_library" title="C standard library">C standard library</a>

<ul><li><a href="Glibc" title="Glibc">glibc</a></li>

<li><a href="UClibc" title="UClibc">uClibc</a></li>

<li><a href="Bionic_(software)" title="Bionic (software)">Bionic</a>

<ul><li><a href="Libhybris" title="Libhybris">libhybris</a></li></ul></li>

<li><a href="Dietlibc" title="Dietlibc">dietlibc</a></li>

<li><a href="Embedded_GLIBC" class="mw-redirect" title="Embedded GLIBC">EGLIBC</a></li>

<li><a href="Klibc" title="Klibc">klibc</a></li>

<li><a href="Newlib" title="Newlib">Newlib</a></li></ul></li>

<li><a href="Cgroups" title="Cgroups">libcgroup</a></li>

<li><a href="Direct_Rendering_Manager" title="Direct Rendering Manager">libdrm</a></li>

<li><a href="Advanced_Linux_Sound_Architecture" title="Advanced Linux Sound Architecture">libalsa</a></li>

<li><a href="Evdev" title="Evdev">libevdev</a></li>

<li><a href="Libusb" title="Libusb">libusb</a></li>

<li><a href="Io_uring" title="Io uring">liburing</a></li></ul>

</div></td></tr></tbody></table><div></div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Components</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em">

<ul><li><a href="Loadable_kernel_module" title="Loadable kernel module">Kernel modules</a></li>

<li><a href="BlueZ" class="mw-redirect" title="BlueZ">BlueZ</a></li>

<li><a href="Cgroups" title="Cgroups">cgroups</a></li>

<li><a href="Linux_console" title="Linux console">Console</a></li>

<li><a href="Bcache" title="Bcache">bcache</a></li>

<li><a href="Device_mapper" title="Device mapper">Device mapper</a></li>

<li><a href="Dm-cache" title="Dm-cache">dm-cache</a></li>

<li><a href="Dm-crypt" title="Dm-crypt">dm-crypt</a></li>

<li><a href="Evdev" title="Evdev">evdev</a></li>

<li><a href="Kernel_same-page_merging" title="Kernel same-page merging">Kernel same-page merging</a> (KSM)</li>

<li><a href="Linux_framebuffer" title="Linux framebuffer">Framebuffer</a></li>

<li><a href="KMS_driver" class="mw-redirect" title="KMS driver">KMS driver</a></li>

<li><a href="Netfilter" title="Netfilter">Netfilter</a></li>

<li><a href="Netlink" title="Netlink">Netlink</a></li>

<li><a href="Nftables" title="Nftables">nftables</a></li>

<li><a href="Network_scheduler" title="Network scheduler">Network scheduler</a></li>

<li><a href="Zswap" title="Zswap">zswap</a></li></ul>

<ul><li><a href="Scheduling_(computing)#Linux" title="Scheduling (computing)">Process and I/O schedulers</a>:</li>

<li><a href="Brain_Fuck_Scheduler" title="Brain Fuck Scheduler">Brain Fuck Scheduler</a></li>

<li><a href="Completely_Fair_Scheduler" title="Completely Fair Scheduler">Completely Fair Scheduler</a> (CFS)</li>

<li><a href="Earliest_eligible_virtual_deadline_first_scheduling" title="Earliest eligible virtual deadline first scheduling">Earliest eligible virtual deadline first</a> (EEVDF)</li>

<li><a href="Noop_scheduler" title="Noop scheduler">Noop scheduler</a></li>

<li><a href="O(n)_scheduler" title="O(n) scheduler">O(n) scheduler</a></li>

<li><a href="O(1)_scheduler" title="O(1) scheduler">O(1) scheduler</a></li>

<li><a href="SCHED_DEADLINE" title="SCHED DEADLINE">SCHED_DEADLINE</a></li>

<li><a href="SCHED_FIFO" class="mw-redirect" title="SCHED FIFO">SCHED_FIFO</a></li>

<li><a href="SCHED_RR" class="mw-redirect" title="SCHED RR">SCHED_RR</a></li></ul>

<ul><li><a href="Linux_Security_Modules" title="Linux Security Modules">Security Modules</a>: <a href="AppArmor" title="AppArmor">AppArmor</a></li>

<li><a href="Exec_Shield" title="Exec Shield">Exec Shield</a></li>

<li><a href="Seccomp" title="Seccomp">seccomp</a></li>

<li><a href="Security-Enhanced_Linux" title="Security-Enhanced Linux">SELinux</a></li>

<li><a href="Smack_(software)" title="Smack (software)">Smack</a></li>

<li><a href="Tomoyo_Linux" title="Tomoyo Linux">Tomoyo Linux</a></li>

<li><a href="Linux_PAM" title="Linux PAM">Linux PAM</a></li></ul>

<ul><li><a href="Device_driver" title="Device driver">Device drivers</a>

<li><a href="Free_and_open-source_graphics_device_driver" title="Free and open-source graphics device driver">graphics</a></li></ul></li>

<li><a href="Raw_device" title="Raw device">Raw device</a></li></ul>

<ul><li><a href="Initramfs" class="mw-redirect" title="Initramfs">initramfs</a></li>

<li><a href="KernelCare" title="KernelCare">KernelCare</a></li>

<li><a href="Kexec" title="Kexec">kexec</a></li>

<li><a href="KGraft" title="KGraft">kGraft</a></li>

<li><a href="Kpatch" title="Kpatch">kpatch</a></li>

<li><a href="Ksplice" title="Ksplice">Ksplice</a></li></ul>

</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Variants</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em">

<ul><li><a href="Mainline_Linux" class="mw-redirect" title="Mainline Linux">Mainline</a>

<ul><li><a href="Linux_kernel" title="Linux kernel">Linux kernel</a></li>

<li><a href="Linux-libre" title="Linux-libre">Linux-libre</a></li></ul></li>

<li><a href="High-performance_computing" title="High-performance computing">High-performance computing</a>

<li><a href="Compute_Node_Linux" title="Compute Node Linux">Compute Node Linux</a></li>

<li><a href="Slurm_Workload_Manager" title="Slurm Workload Manager">SLURM</a></li></ul></li>

<li><a href="Real-time_computing" title="Real-time computing">Real-time computing</a>

<ul><li><a href="RTLinux" title="RTLinux">RTLinux</a></li>

<li><a href="Xenomai" title="Xenomai">Xenomai</a></li>

<li><a href="PREEMPT_RT" title="PREEMPT RT">PREEMPT_RT</a></li></ul></li>

<li><a href="Memory_management_unit" title="Memory management unit">MMU</a>-less

<ul><li><a href="%CE%9CClinux" title="ΜClinux">μClinux</a></li>

<li><a href="PSXLinux" title="PSXLinux">PSXLinux</a></li></ul></li></ul>

</div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th id="Virtualization18" scope="row" class="navbox-group" style="width:1%"><a href="Virtualization" title="Virtualization">Virtualization</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em">

<ul><li><a href="Hypervisor" title="Hypervisor">Hypervisor</a>

<li><a href="OS-level_virtualization" title="OS-level virtualization">OS-level virtualization</a>

<ul><li><a href="Linux-VServer" title="Linux-VServer">Linux-VServer</a></li>

<li><a href="Lguest" title="Lguest">Lguest</a></li>

<li><a href="OpenVZ" title="OpenVZ">OpenVZ</a></li></ul></li>

<li>Other

<ul><li><a href="L4Linux" title="L4Linux">L4Linux</a></li>

<li><a href="User-mode_Linux" title="User-mode Linux">User-mode Linux</a></li>

<li><a href="MkLinux" title="MkLinux">MkLinux</a></li>

<li><a href="Cooperative_Linux" title="Cooperative Linux">coLinux</a></li></ul></li></ul>

</div></td></tr></tbody></table><div>

</div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="Linux_adoption" title="Linux adoption">Adoption</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th id="Rangeof_use48" scope="row" class="navbox-group" style="width:1%"><a href="Linux_range_of_use" title="Linux range of use">Range<br>of use</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em">

<ul><li><a href="Linux_desktop_environments" class="mw-redirect" title="Linux desktop environments">Desktop</a></li>

<li><a href="Linux_on_embedded_systems" title="Linux on embedded systems">Embedded</a></li>

<li><a href="Video_games_and_Linux" title="Video games and Linux">Gaming</a></li>

<li>Thin client:

<li>Server:

<li><a href="Linux-powered_device" title="Linux-powered device">Devices</a></li></ul>

</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Adopters</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em">

<ul><li><a href="List_of_Linux_adopters" title="List of Linux adopters">List of Linux adopters</a></li></ul>

</div></td></tr></tbody></table><div></div></td></tr><tr><td class="navbox-abovebelow" colspan="2"><div>

<ul><li><b><span class="nowrap"><span class="noviewer" typeof="mw:File"></span> </span><a href="Portal%3ALinux" title="Portal:Linux">Linux portal</a></b></li>

<li><b><span class="nowrap"><span class="noviewer" typeof="mw:File"><span></span></span> </span><a href="Portal%3AFree_and_open-source_software" title="Portal:Free and open-source software">Free and open-source software portal</a></b></li>

<li><span class="noviewer" typeof="mw:File"><span title="Category"></span></span> <b>Category</b></li></ul>

</div></td></tr></tbody></table></div></div><div><div class="zim-footer">

This article is issued from <a class="external text" title="Last edited on 2024-06-16" href="https://en.wikipedia.org/wiki/?title=Linux_Virtual_Server&oldid=1229387687">Wikipedia</a>. The text is available under <a class="external text" href="https://creativecommons.org/licenses/by-sa/4.0/deed.en">Creative Commons Attribution-Share Alike 4.0</a> unless otherwise noted. Additional terms may apply for the media files.

</div>

</div></div>

</div>

</main>

</div>

</body></html>