{"id":260,"date":"2016-07-30T17:23:43","date_gmt":"2016-07-30T14:23:43","guid":{"rendered":"https:\/\/community.virtono.com\/?p=260"},"modified":"2016-07-30T17:23:44","modified_gmt":"2016-07-30T14:23:44","slug":"introduction-to-virtualization","status":"publish","type":"post","link":"https:\/\/www.virtono.com\/community\/news-announcements\/introduction-to-virtualization\/","title":{"rendered":"Introduction To Virtualization"},"content":{"rendered":"<p style=\"text-align: center\">At the beginning, before the dawn of time\u00a0 there was <strong>emulation<\/strong>.(overly exaggerated)<\/p>\n<p>\u00a0<strong>Emulation,<\/strong>\u00a0the virtual machine simulates the complete hardware in software. This allows an operating system for one computer architecture to be run on the architecture that the emulator is written for. Sine all operations are run in software, emulation tends to be slower, however can support more platforms since it is hardware independent.<\/p>\n<p>&nbsp;<\/p>\n<p>In emulation, the behavior of a complete computer is copied to a software program. The <strong>emulation<\/strong> layer talks to an operating system which on its turn talks to the computer hardware. The operating system that you want to install in an emulation layer doesn&#8217;t see that it is used in an emulated environemt and therefore you can install it as you are used to install your favourite operating system.<\/p>\n<p>Two popular open source emulators are <strong>QEMU<\/strong> (http:\/\/fabrice.bellard.free.fr\/qemu\/)<\/p>\n<p>Bochs (<a href=\"http:\/\/bochs.sourceforge.net\" target=\"_blank\" rel=\"noopener\">http:\/\/bochs.sourceforge.net<\/a>).<\/p>\n<p>One of the most important properties of emulation, is that all hardware is emulated, the CPU as well.<\/p>\n<p>This has advantages, such as the fact that you can run an operating system that was developed for another architecture on your architecture. With this advantage however, also comes the most important disadvantage; this same option to virtualize a complete CPU comes with a heavy performance price.<\/p>\n<p>In the next generation, virtualization was taken to a higher level. This means that between the emulation layer that was responsible for interpreting instructions from the virtualized machines and the<\/p>\n<p>Hardware, no host operating system was required between virtual machines and hardware anymore.<\/p>\n<p>Instead the virtual machine monitor, also known as the hypervisor was introduced to run directly on the hardware. Because of this new architecture, virtualization became much more efficient. VMware for<\/p>\n<p>example was very successful with this approach as implemented in VMware ESX.<\/p>\n<p>There are however two different approaches when virtualization is used this way. In the old approach all instructions that were generated by the virtualized machine needed to be translated to the appropriate format for the CPU, which involves a lot of work for the hypervisor.<\/p>\n<p>In the new approach which is used by Xen, there is no translation between the instructions that leave the virtualized machine<\/p>\n<p>and the CPU that executes them.<\/p>\n<p>This can be accomplished in two ways.<\/p>\n<p>Option number one is to use a CPU that understands the unmodified instructions that are generated by the virtualized operating system and interprets them (full virtualization).<\/p>\n<p>Option number two is to modify the operating system so that it generates instructions that are optimized for use in a virtualized environment (para virtualization).<\/p>\n<p style=\"text-align: center\"><strong>What is virtualization?<\/strong><\/p>\n<ul>\n<li>virtualization is a broad term that refers to the abstraction<\/li>\n<li>of computer resources.<\/li>\n<li>Server virtualization<\/li>\n<li>\u2013 Hardware \u2013 ex: IBM pSeries and zSeries LPARS<\/li>\n<li>\u2013 Software \u2013 ex: Vmware, Xen, Solaris Containers, SWsoft<\/li>\n<li>Virtuozzo, Virtual Box, KVM<\/li>\n<li>Storage virtulization<\/li>\n<li>\u2013 Hardware \u2013 ex: RAID, SAN<\/li>\n<li>\u2013 Software \u2013 ex: iSCSI, Veratis Storage Foundation, Software<\/li>\n<li>RAID<\/li>\n<\/ul>\n<p><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" data-attachment-id=\"261\" data-permalink=\"https:\/\/www.virtono.com\/community\/news-announcements\/introduction-to-virtualization\/attachment\/1-9\/\" data-orig-file=\"https:\/\/i0.wp.com\/www.virtono.com\/community\/wp-content\/uploads\/2016\/07\/1-6.png?fit=720%2C414&amp;ssl=1\" data-orig-size=\"720,414\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;,&quot;orientation&quot;:&quot;0&quot;}\" data-image-title=\"1\" data-image-description=\"\" data-image-caption=\"\" data-medium-file=\"https:\/\/i0.wp.com\/www.virtono.com\/community\/wp-content\/uploads\/2016\/07\/1-6.png?fit=300%2C173&amp;ssl=1\" data-large-file=\"https:\/\/i0.wp.com\/www.virtono.com\/community\/wp-content\/uploads\/2016\/07\/1-6.png?fit=720%2C414&amp;ssl=1\" class=\"alignnone  wp-image-261\" src=\"https:\/\/i0.wp.com\/community.virtono.com\/wp-content\/uploads\/2016\/07\/1-6-300x173.png?resize=579%2C334&#038;ssl=1\" alt=\"1\" width=\"579\" height=\"334\" srcset=\"https:\/\/i0.wp.com\/www.virtono.com\/community\/wp-content\/uploads\/2016\/07\/1-6.png?resize=300%2C173&amp;ssl=1 300w, https:\/\/i0.wp.com\/www.virtono.com\/community\/wp-content\/uploads\/2016\/07\/1-6.png?w=720&amp;ssl=1 720w\" sizes=\"auto, (max-width: 579px) 100vw, 579px\" \/><\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p style=\"text-align: center\"><strong><br \/>\nVirtual Machines<\/strong><\/p>\n<p style=\"text-align: center\">\n<ul>\n<li><strong> Enabled by layer that sits between the OS and<\/strong><\/li>\n<li><strong>hardware<\/strong><\/li>\n<li><strong>\u2013 OS instances think they are controlling the \u201creal\u201d machine*<\/strong><\/li>\n<li><strong>\u2013 Virtulization layer mediates access to hardware resources<\/strong><\/li>\n<li><strong>\u2013 Permits multiple OS instances to coexist on a single server<\/strong><\/li>\n<li><strong>\u2013 Even incompatible OS&#8217;s can share a single server<\/strong><\/li>\n<li><strong>\u2013 the \u201clayer\u201d is referred to as a Virtual Machine Monitor (VMM)<\/strong><\/li>\n<\/ul>\n<p><strong>\u00a0<\/strong><\/p>\n<p style=\"text-align: center\"><strong>Full versus Para Virtualization<\/strong><\/p>\n<p><strong>\u00a0<\/strong><\/p>\n<ul>\n<li>Full virtualization is one way of handling virtualization. Using this method, the virtual machine talks to a component called the <strong>virtual machine monito<\/strong>r and this virtual machine monitor talks to the hardware platform directly.<\/li>\n<li>To use full virtualization in a Xen environment, you need a CPU that understands unmodified instructions that are generated by the virtualized operating system. Without this special feature on the CPU&#8217;s, it&#8217;s not possible to use full virtualization in Xen.<\/li>\n<li>This is because in the Xen approach not every instruction that is generated by the virtualized operating system is translated to a format that every CPU understands, because this is very resource intensive. Instead, the virtualization feature that is implemented in modern CPU&#8217;s helps the virtualized operating system in a way that it can send out unmodified instructions.<\/li>\n<li>The main advantage of full virtualization, is that an unmodified operating system is installed. This means that virtually every operating system that runs on the same architecture can be virtualized.<\/li>\n<li>The most efficient approach in virtualization, is <strong>para virtualization<\/strong>.<\/li>\n<li>In <strong>para virtualization<\/strong>, the guest operating system uses a specialized <strong>API<\/strong> to talk to the virtual machine monitor which is responsible for handling the virtualization requests and putting them to the real hardware.<\/li>\n<li>Because of this special <strong>API<\/strong>, the virtual machine manager doesn&#8217;t need to do a resource intensive translation of instructions any more before they can be passed to the hardware.<\/li>\n<li>Also, when using the <strong>paravirtualization<\/strong> API, the virtualized operating system is capable of generating much more efficients instructions.<\/li>\n<li>A disadvantage however, is that you do need a modified operating system that includes this specific API and for certain operating systems (Windows mainly) this is an important disadvantage because such an API is not available.<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<p style=\"text-align: center\"><strong>Full Virtualization<\/strong><\/p>\n<p>Full virtualization on CPUs that have been designed specifically for virtualization. (Examples include the next-generation AMD processors with AMD-V.) A fully virtualized operating system is one that has not been modified specifically to run in a virtual environment, so it is unaware that it is being virtualized. As a result, the hypervisor traps and emulates every I\/O and hardware instruction that is deemed privileged by the hypervisor.<\/p>\n<p>Typically, the overhead occurring from these trapping and emulation operations would have a significant impact on performance. However, the AMD processors with AMD-V have been designed specifically for virtualization. The Xen hypervisor interacts with the virtualization extensions in the AMD processors not only to improve performance<\/p>\n<p>and efficiency, but also to provide hardwarebased isolation between these unmodified guest operating systems running on a virtualization server.<\/p>\n<p>The main benefit of full virtualization comes from its ability to host legacy operating systems that have not been paravirtualized. The ability to host these legacy operating systems in a virtualized environment is critical to a data center\u2019s server-consolidation efforts. This feature is mandatory for virtualizing proprietary operating systems, including those from Microsoft*.<\/p>\n<p>&nbsp;<\/p>\n<ul>\n<li>To run full virtualization guests on systems with Hardware-assisted Virtual Machine (HVM), Intel, or AMD platforms, you must check to ensure your CPUs have the capabilities needed to do so.<\/li>\n<li>To check if you have the CPU flags for Intel support, enter the following:<\/li>\n<li>grep vmx \/proc\/cpuinfo<\/li>\n<li>The output displays:<\/li>\n<li>flags :\u00a0 fpu tsc msr pae mce cx8 apic mtrr mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm syscall\u00a0 nx lm constant_tsc pni monitor ds_cpl vmx est tm2 cx16 xtpr lahf_lm<\/li>\n<li>If a vmx flag appears then you have Intel support.<\/li>\n<li>To check if you have the CPU flags for AMD support, enter the following:<\/li>\n<li>grep svm \/proc\/cpuinfo<\/li>\n<li>cat \/proc\/cpuinfo | grep svm<\/li>\n<li>The output displays:<\/li>\n<li>flags :\u00a0 fpu tsc msr pae mce cx8 apic mtrr mca cmov pat pse36 clflush dt acpi mmx fxsr sse sse2 ss ht tm syscall nx mmtext fxsr_opt\u00a0 rdtscp lm 3dnowext\u00a0 pni\u00a0 cx16\u00a0 lahf_lm\u00a0 cmp_legacy\u00a0 svm\u00a0 cr8_legacy<\/li>\n<\/ul>\n<p><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" data-attachment-id=\"262\" data-permalink=\"https:\/\/www.virtono.com\/community\/news-announcements\/introduction-to-virtualization\/attachment\/2-8\/\" data-orig-file=\"https:\/\/i0.wp.com\/www.virtono.com\/community\/wp-content\/uploads\/2016\/07\/2-5.png?fit=338%2C488&amp;ssl=1\" data-orig-size=\"338,488\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;,&quot;orientation&quot;:&quot;0&quot;}\" data-image-title=\"2\" data-image-description=\"\" data-image-caption=\"\" data-medium-file=\"https:\/\/i0.wp.com\/www.virtono.com\/community\/wp-content\/uploads\/2016\/07\/2-5.png?fit=208%2C300&amp;ssl=1\" data-large-file=\"https:\/\/i0.wp.com\/www.virtono.com\/community\/wp-content\/uploads\/2016\/07\/2-5.png?fit=338%2C488&amp;ssl=1\" class=\"wp-image-262 aligncenter\" src=\"https:\/\/i0.wp.com\/community.virtono.com\/wp-content\/uploads\/2016\/07\/2-5-208x300.png?resize=250%2C361&#038;ssl=1\" alt=\"2\" width=\"250\" height=\"361\" srcset=\"https:\/\/i0.wp.com\/www.virtono.com\/community\/wp-content\/uploads\/2016\/07\/2-5.png?resize=208%2C300&amp;ssl=1 208w, https:\/\/i0.wp.com\/www.virtono.com\/community\/wp-content\/uploads\/2016\/07\/2-5.png?w=338&amp;ssl=1 338w\" sizes=\"auto, (max-width: 250px) 100vw, 250px\" \/><\/p>\n<p>&nbsp;<\/p>\n<p style=\"text-align: center\"><strong>\u00a0Paravirtualization<\/strong><\/p>\n<p>Xen\u2019s unique performance benefits accrue\u00a0 from its use of paravirtualization. With paravirtualization,the operating system running inside of a virtual machine (known as a guest operating system) is modified to run on top of a hypervisor.<\/p>\n<p>virtualized operating system instance is aware that it is running in a virtualized state and has been fine-tuned for optimal performance<\/p>\n<p>in that environment.<\/p>\n<p>Paravirtualization allows the hypervisor to avoid hard-to-virtualize processor instructions by replacing them with procedure calls that<br \/>\nprovide that functionality. A paravirtualized operating system loads and runs virtual drivers that are capable of interacting with Xen to access resources on the host virtual server. In other words, it does not require complete emulation of computer devices.<\/p>\n<p><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" data-attachment-id=\"263\" data-permalink=\"https:\/\/www.virtono.com\/community\/news-announcements\/introduction-to-virtualization\/attachment\/3-7\/\" data-orig-file=\"https:\/\/i0.wp.com\/www.virtono.com\/community\/wp-content\/uploads\/2016\/07\/3-4.png?fit=288%2C528&amp;ssl=1\" data-orig-size=\"288,528\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;,&quot;orientation&quot;:&quot;0&quot;}\" data-image-title=\"3\" data-image-description=\"\" data-image-caption=\"\" data-medium-file=\"https:\/\/i0.wp.com\/www.virtono.com\/community\/wp-content\/uploads\/2016\/07\/3-4.png?fit=164%2C300&amp;ssl=1\" data-large-file=\"https:\/\/i0.wp.com\/www.virtono.com\/community\/wp-content\/uploads\/2016\/07\/3-4.png?fit=288%2C528&amp;ssl=1\" class=\"aligncenter wp-image-263\" src=\"https:\/\/i0.wp.com\/community.virtono.com\/wp-content\/uploads\/2016\/07\/3-4-164x300.png?resize=250%2C458&#038;ssl=1\" alt=\"3\" width=\"250\" height=\"458\" srcset=\"https:\/\/i0.wp.com\/www.virtono.com\/community\/wp-content\/uploads\/2016\/07\/3-4.png?resize=164%2C300&amp;ssl=1 164w, https:\/\/i0.wp.com\/www.virtono.com\/community\/wp-content\/uploads\/2016\/07\/3-4.png?w=288&amp;ssl=1 288w\" sizes=\"auto, (max-width: 250px) 100vw, 250px\" \/><\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>At the beginning, before the dawn of time\u00a0 there was emulation.(overly exaggerated) \u00a0Emulation,\u00a0the virtual machine simulates the complete hardware in software. This allows an operating system for one computer architecture to be run on the architecture that the emulator is written for. Sine all operations are run in software, emulation<\/p>\n","protected":false},"author":3,"featured_media":265,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[1],"tags":[],"class_list":["post-260","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-news-announcements"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"https:\/\/i0.wp.com\/www.virtono.com\/community\/wp-content\/uploads\/2016\/07\/ic-2.jpg?fit=940%2C266&ssl=1","jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p7ISfL-4c","jetpack_likes_enabled":true,"jetpack-related-posts":[{"id":218,"url":"https:\/\/www.virtono.com\/community\/knowledgebase\/introduction-to-server\/","url_meta":{"origin":260,"position":0},"title":"INTRODUCTION TO SERVER","author":"Daniel Draga","date":"July 30, 2016","format":false,"excerpt":"Servers are the one that is responsible to provide response to each client\u2019s request simultaneously. A Server may be responsible to process a single request or more than one request at a time. \u00a0 A\u00a0server\u00a0is a system (software\u00a0and suitable\u00a0computer hardware) that responds to requests across a\u00a0computer network\u00a0to provide, or help\u2026","rel":"","context":"In &quot;Knowledgebase&quot;","block_context":{"text":"Knowledgebase","link":"https:\/\/www.virtono.com\/community\/category\/knowledgebase\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.virtono.com\/community\/wp-content\/uploads\/2016\/07\/server-rack1.jpg?fit=1200%2C857&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.virtono.com\/community\/wp-content\/uploads\/2016\/07\/server-rack1.jpg?fit=1200%2C857&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/www.virtono.com\/community\/wp-content\/uploads\/2016\/07\/server-rack1.jpg?fit=1200%2C857&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/www.virtono.com\/community\/wp-content\/uploads\/2016\/07\/server-rack1.jpg?fit=1200%2C857&ssl=1&resize=700%2C400 2x, https:\/\/i0.wp.com\/www.virtono.com\/community\/wp-content\/uploads\/2016\/07\/server-rack1.jpg?fit=1200%2C857&ssl=1&resize=1050%2C600 3x"},"classes":[]},{"id":97,"url":"https:\/\/www.virtono.com\/community\/knowledgebase\/what-is-the-difference-between-kvm-and-openvz-virtualization\/","url_meta":{"origin":260,"position":1},"title":"What is the difference between KVM and OpenVZ virtualization?","author":"Virtono","date":"July 18, 2016","format":false,"excerpt":"\u00a0 VS \u00a0What is the difference between KVM and OpenVZ? Usually this question arises when a person is looking for a Virtual Private Server, it\u2019s a dilemma, isn\u2019t it? Weighing the pros and cons but one thing that should be kept in mind is that out of these two, there\u2026","rel":"","context":"In &quot;Knowledgebase&quot;","block_context":{"text":"Knowledgebase","link":"https:\/\/www.virtono.com\/community\/category\/knowledgebase\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.virtono.com\/community\/wp-content\/uploads\/2016\/07\/1-2.jpg?fit=1024%2C768&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.virtono.com\/community\/wp-content\/uploads\/2016\/07\/1-2.jpg?fit=1024%2C768&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/www.virtono.com\/community\/wp-content\/uploads\/2016\/07\/1-2.jpg?fit=1024%2C768&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/www.virtono.com\/community\/wp-content\/uploads\/2016\/07\/1-2.jpg?fit=1024%2C768&ssl=1&resize=700%2C400 2x"},"classes":[]},{"id":2144,"url":"https:\/\/www.virtono.com\/community\/knowledgebase\/the-best-linux-distributions-for-old-hardware\/","url_meta":{"origin":260,"position":2},"title":"The best Linux distributions for old hardware","author":"Shreyash Sharma","date":"December 15, 2020","format":false,"excerpt":"There is no hardware for which a working Linux is not available.\u00a0Finding the right role for old hardware and the right board and system for a planned role is still complicated. For a practical presentation, almost each of the following aspects would have deserved its own workshop.\u00a0This entry-level contribution to\u2026","rel":"","context":"In &quot;Knowledgebase&quot;","block_context":{"text":"Knowledgebase","link":"https:\/\/www.virtono.com\/community\/category\/knowledgebase\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.virtono.com\/community\/wp-content\/uploads\/2020\/12\/Which-Distro1.png?fit=705%2C273&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.virtono.com\/community\/wp-content\/uploads\/2020\/12\/Which-Distro1.png?fit=705%2C273&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/www.virtono.com\/community\/wp-content\/uploads\/2020\/12\/Which-Distro1.png?fit=705%2C273&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/www.virtono.com\/community\/wp-content\/uploads\/2020\/12\/Which-Distro1.png?fit=705%2C273&ssl=1&resize=700%2C400 2x"},"classes":[]},{"id":2283,"url":"https:\/\/www.virtono.com\/community\/knowledgebase\/introduction-to-docker-containers-vms\/","url_meta":{"origin":260,"position":3},"title":"Introduction to Docker, Containers &#038; VMs","author":"Shreyash Sharma","date":"March 6, 2021","format":false,"excerpt":"In this introductory section, we will go over the need for virtualisation, the necessity which gave birth to it. We will cover a brief history and how the future looks for this industry. If you want to get hands-on real-world experience with understanding and deploying Docker Containers. Or if you\u2026","rel":"","context":"In &quot;Knowledgebase&quot;","block_context":{"text":"Knowledgebase","link":"https:\/\/www.virtono.com\/community\/category\/knowledgebase\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.virtono.com\/community\/wp-content\/uploads\/2021\/02\/461265-docker-containers.jpg?fit=1200%2C675&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.virtono.com\/community\/wp-content\/uploads\/2021\/02\/461265-docker-containers.jpg?fit=1200%2C675&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/www.virtono.com\/community\/wp-content\/uploads\/2021\/02\/461265-docker-containers.jpg?fit=1200%2C675&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/www.virtono.com\/community\/wp-content\/uploads\/2021\/02\/461265-docker-containers.jpg?fit=1200%2C675&ssl=1&resize=700%2C400 2x, https:\/\/i0.wp.com\/www.virtono.com\/community\/wp-content\/uploads\/2021\/02\/461265-docker-containers.jpg?fit=1200%2C675&ssl=1&resize=1050%2C600 3x"},"classes":[]},{"id":813,"url":"https:\/\/www.virtono.com\/community\/knowledgebase\/firewall-what-how-hardware-vs-software-firewall\/","url_meta":{"origin":260,"position":4},"title":"FIREWALL | What? How? | Hardware vs. Software Firewall","author":"Daniel Draga","date":"December 14, 2016","format":false,"excerpt":"Firewalls are basically a barrier between your computer (or a network) and the Internet (outside world). A firewall can be simply compared to a security guard who stands at the entrance of your house and filters the visitors coming to your place. 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