{"id":93978,"date":"2026-10-27T10:10:18","date_gmt":"2026-10-27T03:10:18","guid":{"rendered":"https:\/\/itsystems.vn\/das-vs-nas-vs-san-vsa-business-storage-architecture\/"},"modified":"2026-10-27T10:10:18","modified_gmt":"2026-10-27T03:10:18","slug":"das-vs-nas-vs-san-vsa-business-storage-architecture","status":"publish","type":"post","link":"https:\/\/itsystems.vn\/en\/das-vs-nas-vs-san-vsa-business-storage-architecture\/","title":{"rendered":"DAS vs NAS vs SAN vs VSA: Business Storage Architecture"},"content":{"rendered":"<p><strong>Short answer:<\/strong> Direct-attached storage (DAS) connects directly to one server or computer. Network-attached storage (NAS) commonly serves shared files over a network. A storage area network (SAN) is a managed storage-network architecture that presents block volumes to hosts. A virtual storage appliance (VSA) is different: it describes software deployed as a VM, which may expose file or block interfaces depending on the product. Choose by application access type, host count, latency, operating capacity and recovery objectives, not by acronyms or raw terabytes.<\/p>\n<p>This is an architecture comparison. If the question is cloud, NAS or portable media for staff, read <a href='https:\/\/itsystems.vn\/en\/cloud-vs-nas-vs-external-drive-business-storage\/'>the workplace-and-copy comparison<\/a>. For NAS model sizing see <a href='https:\/\/itsystems.vn\/en\/how-to-choose-business-nas-storage\/'>the selection checklist<\/a>. <a href='https:\/\/itsystems.vn\/en\/business-synology-solutions\/'>Synology solutions<\/a> are one deployment route, not the default answer to every workload.<\/p>\n<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_89 counter-hierarchy ez-toc-counter ez-toc-light-blue ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">The content of the article<\/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:\/\/itsystems.vn\/en\/das-vs-nas-vs-san-vsa-business-storage-architecture\/#The_four_terms_describe_two_different_dimensions\" >The four terms describe two different dimensions<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/itsystems.vn\/en\/das-vs-nas-vs-san-vsa-business-storage-architecture\/#DAS_close_to_one_host_simple_but_not_directly_shared\" >DAS: close to one host, simple but not directly shared<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/itsystems.vn\/en\/das-vs-nas-vs-san-vsa-business-storage-architecture\/#NAS_governed_shared_files\" >NAS: governed shared files<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/itsystems.vn\/en\/das-vs-nas-vs-san-vsa-business-storage-architecture\/#SAN_block_volumes_for_hosts_over_a_managed_fabric\" >SAN: block volumes for hosts over a managed fabric<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/itsystems.vn\/en\/das-vs-nas-vs-san-vsa-business-storage-architecture\/#VSA_storage_software_on_virtual_infrastructure\" >VSA: storage software on virtual infrastructure<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/itsystems.vn\/en\/das-vs-nas-vs-san-vsa-business-storage-architecture\/#Fast_decision_matrix_and_acceptance_test\" >Fast decision matrix and acceptance test<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/itsystems.vn\/en\/das-vs-nas-vs-san-vsa-business-storage-architecture\/#Frequently_asked_questions\" >Frequently asked questions<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-8\" href=\"https:\/\/itsystems.vn\/en\/das-vs-nas-vs-san-vsa-business-storage-architecture\/#Can_a_NAS_present_iSCSI\" >Can a NAS present iSCSI?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-9\" href=\"https:\/\/itsystems.vn\/en\/das-vs-nas-vs-san-vsa-business-storage-architecture\/#Does_SAN_always_mean_Fibre_Channel\" >Does SAN always mean Fibre Channel?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-10\" href=\"https:\/\/itsystems.vn\/en\/das-vs-nas-vs-san-vsa-business-storage-architecture\/#Is_VSA_a_fourth_storage_type_like_NAS\" >Is VSA a fourth storage type like NAS?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-11\" href=\"https:\/\/itsystems.vn\/en\/das-vs-nas-vs-san-vsa-business-storage-architecture\/#Do_RAID_and_multipath_replace_backup\" >Do RAID and multipath replace backup?<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-12\" href=\"https:\/\/itsystems.vn\/en\/das-vs-nas-vs-san-vsa-business-storage-architecture\/#Technical_sources\" >Technical sources<\/a><\/li><\/ul><\/nav><\/div>\n<h2><span class=\"ez-toc-section\" id=\"The_four_terms_describe_two_different_dimensions\"><\/span>The four terms describe two different dimensions<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>DAS, NAS and SAN usually describe how storage is attached or delivered: directly to a host, as shared files over a network, or as block volumes across a storage fabric. A modern appliance may support SMB\/NFS and iSCSI on compatible models. Therefore, the shape of a box does not uniquely define the access protocol. First ask whether the application needs a file share, a block volume for virtualization\/databases, or a backup repository.<\/p>\n<p>VSA describes the <em>software deployment form<\/em> of a storage appliance running as a VM. It still depends on physical CPU, memory, disks and networking, licensing, and host failure domains. Depending on the product it can present SMB\/NFS, iSCSI or a gateway interface. Claims that &#8216;VSA is faster than SAN&#8217; are meaningless without underlying disks, protocol, network and redundancy design.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"DAS_close_to_one_host_simple_but_not_directly_shared\"><\/span>DAS: close to one host, simple but not directly shared<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>DAS includes internal server drives and directly connected enclosures or media. It may suit boot volumes, single-host applications and scratch data when a short data path and straightforward ownership matter. Initial complexity can be low, but moving workloads between hosts, simultaneous sharing, expansion and protection against host loss need separate design.<\/p>\n<p>Do not assume a USB disk is production-grade database or VM storage. Verify controller and drive support, RAID or hot-swap where relevant, replacement plan, maintenance window and an off-host copy. If the requirement is merely portable backup media, use the <a href='https:\/\/itsystems.vn\/en\/cloud-vs-nas-vs-external-drive-business-storage\/'>cloud\u2013NAS\u2013external-drive comparison<\/a> rather than buying a SAN.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"NAS_governed_shared_files\"><\/span>NAS: governed shared files<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>NAS commonly publishes SMB\/NFS files over the LAN. It can fit departmental folders, documents, media and some backup repositories with multi-user access. Size for concurrent sessions, file types, usable capacity after drive protection, network, supported snapshot\/backup functions and an operator. Synology package and volume capabilities vary by model and DSM release.<\/p>\n<p>A NAS does not automatically replace block storage for every hypervisor, database or ERP. Some supported NAS models can present iSCSI LUNs as block storage; then initiators, multipath and host filesystem or cluster rules must be managed. Never mount one writable LUN on several ordinary hosts as if it were a normal SMB folder.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"SAN_block_volumes_for_hosts_over_a_managed_fabric\"><\/span>SAN: block volumes for hosts over a managed fabric<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>A SAN lets hosts access block volumes through a dedicated storage network\/fabric. Fibre Channel and iSCSI are common implementation families. Beyond a file share, a SAN project requires zoning or access control, LUN mapping, multipath, switching, firmware, capacity monitoring and an operating team. It may fit virtualization clusters, transactional systems and supported shared-block HA workloads; most small offices do not automatically need that complexity and cost.<\/p>\n<p>Do not promise that SAN is always faster than NAS. Measure IOPS, throughput, latency, block size, network and concurrency on real workloads. A SAN does not eliminate backup or disaster recovery: logical deletion, bad configuration and corruption can affect many hosts. Validate hypervisor\/application support and failover before procurement.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"VSA_storage_software_on_virtual_infrastructure\"><\/span>VSA: storage software on virtual infrastructure<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>A VSA may turn host resources into a storage service or act as a gateway to another backend, depending on its vendor. For example, AWS Storage Gateway can run as a VM and provide file or iSCSI interfaces depending on gateway type. This illustrates why VSA is not a single protocol or performance tier. Other software-defined or hyperconverged offerings have their own HA and licensing rules that must be checked product by product.<\/p>\n<p>A failed VSA host, network path, full underlying datastore or unrecoverable appliance VM may take down storage service. Examine bootstrap dependencies if the host needs storage provided by that same VSA to start. A pilot must cover recovery of the appliance VM, configuration, access keys and backend data, not only a VM snapshot.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Fast_decision_matrix_and_acceptance_test\"><\/span>Fast decision matrix and acceptance test<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><strong>One host and one application:<\/strong> evaluate suitable DAS, plus an off-host backup. <strong>Shared team files:<\/strong> evaluate NAS or a file server with SMB\/NFS, a permission matrix and a healthy network. <strong>Several hosts requiring supported block access:<\/strong> evaluate SAN or another supported block product with its fabric and operating burden. <strong>Existing virtualization and a specific gateway\/SDS requirement:<\/strong> consider a VSA only after checking compatibility, failure domain, bootstrap, licensing and vendor support.<\/p>\n<p>For any option, inventory applications and protocols, usable capacity, two-year growth, representative IOPS\/latency, RPO\/RTO, warranty, alert owner, a copy outside the failure domain and a tested restore. Accept against real workloads: file and permission behavior, loss of one supported path or host, sample recovery and measured time. Review <a href='https:\/\/itsystems.vn\/en\/quan-tri-he-thong-it\/business-data-backup-management\/'>business backup management<\/a> and <a href='https:\/\/itsystems.vn\/store\/brand\/synology\/'>Synology models in Store<\/a> where NAS fits.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Frequently_asked_questions\"><\/span>Frequently asked questions<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<h3><span class=\"ez-toc-section\" id=\"Can_a_NAS_present_iSCSI\"><\/span>Can a NAS present iSCSI?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Some models can. An iSCSI LUN appears to the host as block storage; validate model support and design initiators, multipath, access and filesystem rules.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Does_SAN_always_mean_Fibre_Channel\"><\/span>Does SAN always mean Fibre Channel?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>No. Fibre Channel is one common fabric; iSCSI can deliver block storage over an appropriately designed IP network.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Is_VSA_a_fourth_storage_type_like_NAS\"><\/span>Is VSA a fourth storage type like NAS?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>No. VSA describes software packaged as a virtual appliance; a particular product may expose files, blocks or a gateway service.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Do_RAID_and_multipath_replace_backup\"><\/span>Do RAID and multipath replace backup?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>No. They mitigate selected disk and path faults, not deletion, ransomware or logical failure. Keep an independent copy and perform restore tests.<\/p>\n<aside class=\"its-post-cta\" style=\"background:#eaf7f6;border-left:4px solid #087e79;padding:20px;margin:28px 0;color:#123047\"><strong>Need to select storage architecture for servers and teams?<\/strong><\/p>\n<p>Share applications, host and user count, file types, I\/O load, network design and recovery objectives. IT Systems can assess DAS\/NAS\/SAN\/VSA, run an appropriate pilot and document recovery acceptance before procurement.<\/p>\n<p><a href='https:\/\/itsystems.vn\/en\/business-synology-solutions\/'>Explore Synology solutions<\/a> \u00b7 <a href='https:\/\/itsystems.vn\/en\/contact-it-systems\/'>Request an assessment<\/a> \u00b7 <a href='tel:02839950359'>+84 28 3995 0359<\/a><\/p>\n<\/aside>\n<h2><span class=\"ez-toc-section\" id=\"Technical_sources\"><\/span>Technical sources<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><a href=\"https:\/\/www.ibm.com\/think\/topics\/data-storage\" target=\"_blank\" rel=\"noopener\">IBM: DAS and storage architectures<\/a>; <a href=\"https:\/\/www.ibm.com\/think\/topics\/san-vs-nas\" target=\"_blank\" rel=\"noopener\">IBM: SAN vs NAS<\/a>; <a href=\"https:\/\/learn.microsoft.com\/en-us\/windows-server\/failover-clustering\/storage-architectures\" target=\"_blank\" rel=\"noopener\">Microsoft: Windows cluster storage architectures<\/a>; <a href=\"https:\/\/aws.amazon.com\/storagegateway\/faqs\/\" target=\"_blank\" rel=\"noopener\">AWS: virtual gateway appliance<\/a>. Confirm product version and application support for any deployment.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Compare DAS, NAS, SAN and VSA by file\/block access, connectivity, operations, recovery and workload before choosing business storage.<\/p>\n","protected":false},"author":68,"featured_media":93976,"comment_status":"","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"rank_math_focus_keyword":"","rank_math_title":"DAS vs NAS vs SAN vs VSA: Business Storage Architecture | IT Systems","rank_math_description":"Compare DAS, NAS, SAN and VSA by file\/block access, connectivity, operations, recovery and workload before choosing business storage.","rank_math_robots":"","rank_math_canonical_url":"","rank_math_schema":"","footnotes":""},"categories":[1344],"tags":[],"class_list":["post-93978","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-uncategorized-en"],"wpml_current_locale":"en_US","wpml_translations":{"vi_VN":{"locale":"vi_VN","id":9104,"slug":"cac-thiet-bi-luu-tru-du-lieu-nen-lua-cho-das-san-nas-hay-vsa","post_title":"DAS, NAS, SAN v\u00e0 VSA kh\u00e1c nhau th\u1ebf n\u00e0o? 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