{"id":2058,"date":"2021-12-03T02:11:00","date_gmt":"2021-12-03T02:11:00","guid":{"rendered":"https:\/\/www.prolimehost.com\/blogs\/?p=2058"},"modified":"2022-06-23T18:23:00","modified_gmt":"2022-06-23T18:23:00","slug":"burst-versus-swap-memory","status":"publish","type":"post","link":"https:\/\/www.prolimehost.com\/blogs\/burst-versus-swap-memory\/","title":{"rendered":"Burst Versus Swap Memory"},"content":{"rendered":"<div class=\"wp-block-image\">\n<figure class=\"aligncenter is-resized\"><img decoding=\"async\" src=\"https:\/\/www.prolimehost.com\/wp-content\/uploads\/sites\/4\/2016\/01\/OpenVZ-vs-XEN.jpg\" alt=\"OpenVZ vs XEN\" class=\"wp-image-418\" width=\"454\" height=\"316\"\/><\/figure>\n<\/div>\n\n\n<p>Burst versus swap memory discussions are normally\u00a0comparisons of OpenVZ versus Xen memory management. There are advantages and disadvantages to each, with burst associated with VZ and swap to Xen. Assuming everything else is equal, which would you consider is the better option \u2013 1024MB guaranteed (SLM) or 768MB guaranteed (burstable to 2048MB)?<\/p>\n\n\n\n<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_80 counter-hierarchy ez-toc-counter ez-toc-grey ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">Table of Contents<\/p>\n<span class=\"ez-toc-title-toggle\"><a href=\"#\" class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" aria-label=\"Toggle Table of Content\"><span class=\"ez-toc-js-icon-con\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #999;color:#999\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewBox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #999;color:#999\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewBox=\"0 0 24 24\" version=\"1.2\" baseProfile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/span><\/a><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1 ' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/www.prolimehost.com\/blogs\/burst-versus-swap-memory\/#I_recently_read_of_an_experiment_pairing_the_two_technologies_under_load_conditions\" >I recently read of an experiment\u00a0pairing the two technologies under load conditions.<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/www.prolimehost.com\/blogs\/burst-versus-swap-memory\/#So_what_can_we_take_away_from_this_test\" >So what can we take away from this test?\u00a0<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/www.prolimehost.com\/blogs\/burst-versus-swap-memory\/#Beyond_guaranteed_to_burst_and_swap_access_latency_on_RAM_burst_is_measured_in_nanoseconds_whereas_swap_HDD_is_measured_in_milliseconds_much_much_slower\" >Beyond guaranteed to burst and swap\u00a0access latency on RAM (burst) is measured in nanoseconds whereas swap (HDD) is measured in milliseconds (much, much slower).<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/www.prolimehost.com\/blogs\/burst-versus-swap-memory\/#Overselling_can_be_an_issue_with_OpenVZ_eg_killing_your_application_if_it_bursts_beyond_the_guaranteed_resource_allocation_instead_of_simply_slowing_down_as_with_a_true_dedicated_server\" >Overselling can be\u00a0an issue with OpenVZ, e.g., killing your application if it bursts beyond the guaranteed resource allocation, instead of simply slowing down as with a true dedicated server.<\/a><ul class='ez-toc-list-level-4' ><li class='ez-toc-heading-level-4'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/www.prolimehost.com\/blogs\/burst-versus-swap-memory\/#BROUGHT_TO_YOU_BY_PROLIMEHOST\" >BROUGHT TO YOU BY PROLIMEHOST<\/a><ul class='ez-toc-list-level-5' ><li class='ez-toc-heading-level-5'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/www.prolimehost.com\/blogs\/burst-versus-swap-memory\/#VPS_SERVICES_LIGHTNING_FAST_SSD_VIRTUAL_SERVERS\" >VPS SERVICES: LIGHTNING FAST SSD VIRTUAL SERVERS<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-5'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/www.prolimehost.com\/blogs\/burst-versus-swap-memory\/#DEDICATED_SERVERS_BACKED_BY_A_999_SLA_NETWORK_UPTIME_GUARANTEE\" >DEDICATED SERVERS: BACKED BY A 99.9% SLA NETWORK UPTIME GUARANTEE<\/a><\/li><\/ul><\/li><\/ul><\/li><\/ul><\/li><\/ul><\/nav><\/div>\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"I_recently_read_of_an_experiment_pairing_the_two_technologies_under_load_conditions\"><\/span>I recently read of an experiment\u00a0pairing the two technologies under load conditions. <span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>The test involved an OpenVZ container (512MB dedicated RAM with 512MB burst) versus a XEN based VPS (768MB with swap). A basic Debian 5 64 bit OS was installed on each with LAMP, email and Jabber\/XMPP. The total <a href=\"https:\/\/openvz.org\/\" title=\"OpenVZ\">OpenVZ<\/a> memory usage equaled 445MB versus XEN\u2019s 296MB.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"So_what_can_we_take_away_from_this_test\"><\/span>So what can we take away from this test?\u00a0<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p>If you\u2019re running Java or other applications that tend to allocate large amounts of virtual memory, <a href=\"https:\/\/openvz.org\/\" target=\"_blank\" rel=\"noreferrer noopener nofollow\">OpenVZ<\/a> containers (without burst) will have less guaranteed memory available. Enter burst .. OpenVZ needs an appropriate amount of burst (usually 1.5 to 2 times the guaranteed).<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Beyond_guaranteed_to_burst_and_swap_access_latency_on_RAM_burst_is_measured_in_nanoseconds_whereas_swap_HDD_is_measured_in_milliseconds_much_much_slower\"><\/span>Beyond guaranteed to burst and swap\u00a0access latency on RAM (burst) is measured in nanoseconds whereas swap (HDD) is measured in milliseconds (much, much slower). <span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p>Swap is slow, so you want ample guaranteed (SLM) to handle your applications. Plus, your system cannot execute stuff out of swap. It has to be in active RAM to execute. With both burst and swap, you want just enough allocation to handle inactive data, keeping as much active data in guaranteed RAM as possible.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Overselling_can_be_an_issue_with_OpenVZ_eg_killing_your_application_if_it_bursts_beyond_the_guaranteed_resource_allocation_instead_of_simply_slowing_down_as_with_a_true_dedicated_server\"><\/span>Overselling can be\u00a0an issue with OpenVZ, e.g., killing your application if it bursts beyond the guaranteed resource allocation, instead of simply slowing down as with a true dedicated server. <span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p>The kernel of <a href=\"https:\/\/www.virtuozzo.com\/\" target=\"_blank\" rel=\"noreferrer noopener nofollow\">Virtuozzo<\/a> cannot be modified as it\u2019s based on an OS template. By contrast (using default settings), Xen doesn\u2019t allow overselling, so a physical server with 16GB of RAM would be limited to 64 x 256MB virtual machines. Plus, XEN allows you to fully modify the kernel, so advanced users can compile and load their own modules, resulting in properly virtualized memory, IO and scheduler that\u2019s stable and predictable.<\/p>\n\n\n\n<h4 class=\"wp-block-heading\"><img decoding=\"async\" src=\"https:\/\/www.prolimehost.com\/wp-content\/uploads\/sites\/4\/2014\/08\/unnamed-e1408122780935.jpg\" alt=\"ProlimeHost\" width=\"400\" height=\"80\"><\/h4>\n\n\n\n<h4 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"BROUGHT_TO_YOU_BY_PROLIMEHOST\"><\/span>BROUGHT TO YOU BY PROLIMEHOST<span class=\"ez-toc-section-end\"><\/span><\/h4>\n\n\n\n<p>We\u2019ve been in the web hosting industry for over a decade, helping hundreds of clients succeed in what they do best and that\u2019s running their business. We specialize in Virtual Private Servers (VPS) and dedicated servers, with data centers in Los Angeles, Denver &amp; Singapore.<\/p>\n\n\n\n<h5 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"VPS_SERVICES_LIGHTNING_FAST_SSD_VIRTUAL_SERVERS\"><\/span>VPS SERVICES: LIGHTNING FAST SSD VIRTUAL SERVERS<span class=\"ez-toc-section-end\"><\/span><\/h5>\n\n\n\n<p>Our&nbsp;<a href=\"https:\/\/www.prolimehost.com\/ssd-vps-server\/\">Virtual Private Servers<\/a>&nbsp;all feature high performance Xeon processors and SSD storage in a RAID10 configuration to optimize your server\u2019s performance, which dramatically enhances visitor experiences on your site.<\/p>\n\n\n\n<p>That speed is backed by unparalleled 24\/7 support, featuring both outstanding response AND resolution times to maximize your uptime.<\/p>\n\n\n\n<p><strong><em>Now is the time to join the ProlimeHost virtual private server revolution.<\/em><\/strong><\/p>\n\n\n\n<h5 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"DEDICATED_SERVERS_BACKED_BY_A_999_SLA_NETWORK_UPTIME_GUARANTEE\"><\/span>DEDICATED SERVERS: BACKED BY A 99.9% SLA NETWORK UPTIME GUARANTEE<span class=\"ez-toc-section-end\"><\/span><\/h5>\n\n\n\n<p>We only use enterprise-class hardware in our&nbsp;<a href=\"https:\/\/www.prolimehost.com\/los-angeles-dedicated-servers\/\">dedicated servers<\/a>&nbsp;[1] and offer a four (4) hour hardware replacement. Throw in IPMI for remote management, support for public and private networks, free operating system (OS) re-installs, and SATA, SAS &amp; SSD (including NVMe) storage. Call 1-877-477-9454 or&nbsp;<a href=\"https:\/\/www.prolimehost.com\/contact\/\">contact us<\/a>&nbsp;[2]. For everything from gaming servers to&nbsp;<a href=\"https:\/\/www.prolimehost.com\/discounted-dedicated-server-deals\/\">cheap dedicated servers<\/a>, we\u2019re here to help.<\/p>\n","protected":false},"excerpt":{"rendered":"Burst versus swap memory discussions are normally\u00a0comparisons of OpenVZ versus Xen memory management. There are advantages and disadvantages&hellip;","protected":false},"author":3,"featured_media":418,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"csco_display_header_overlay":false,"csco_singular_sidebar":"","csco_page_header_type":"","footnotes":""},"categories":[1],"tags":[],"class_list":{"0":"post-2058","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-geneal","8":"cs-entry"},"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.prolimehost.com\/blogs\/wp-json\/wp\/v2\/posts\/2058","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.prolimehost.com\/blogs\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.prolimehost.com\/blogs\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.prolimehost.com\/blogs\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/www.prolimehost.com\/blogs\/wp-json\/wp\/v2\/comments?post=2058"}],"version-history":[{"count":0,"href":"https:\/\/www.prolimehost.com\/blogs\/wp-json\/wp\/v2\/posts\/2058\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.prolimehost.com\/blogs\/wp-json\/wp\/v2\/media\/418"}],"wp:attachment":[{"href":"https:\/\/www.prolimehost.com\/blogs\/wp-json\/wp\/v2\/media?parent=2058"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.prolimehost.com\/blogs\/wp-json\/wp\/v2\/categories?post=2058"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.prolimehost.com\/blogs\/wp-json\/wp\/v2\/tags?post=2058"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}