--- description: Direct Attached Storage (DAS), the name is pretty self-explanatory. A disk subsystem that is directly connected to a host rather than going through a... title: What is Direct Attached Storage (DAS)? image: https://www.storagereview.com/wp-content/uploads/2012/08/HP-DAS-thumb.png --- [![Storage Review]()](https://storagereview.com/) --- [Facebook](https://www.facebook.com/@storagereview) [X (Twitter)](https://twitter.twitter.com/storagereview) [Instagram](https://www.instagram.com/storagereview/) [LinkedIn](https://www.linkedin.com/company/storagereview-com) [YouTube](https://www.youtube.com/user/storagereview?sub_confirmation=1) [Email](mailto:info@storagereview.com) [Spotify](https://open.spotify.com/show/1y6VnznABhHeOSMOmbDTz0) [Reddit](https://www.reddit.com/r/StorageReview/) [Discord](https://discord.gg/TwMHb4azdC) [RSS Feed](https://www.storagereview.com/rss.xml) [TikTok](https://www.tiktok.com/@storagereview) [Facebook](https://www.facebook.com/@storagereview) [X (Twitter)](https://twitter.com/storagereview) [Instagram](https://www.instagram.com/storagereview/) [LinkedIn](https://www.linkedin.com/company/storagereview-com) [YouTube](https://www.youtube.com/user/storagereview?sub_confirmation=1) [Email](mailto:info@storagereview.com) [Spotify](https://open.spotify.com/show/1y6VnznABhHeOSMOmbDTz0) [Reddit](https://www.reddit.com/r/StorageReview/) [Discord](https://discord.gg/TwMHb4azdC) [RSS Feed](https://www.storagereview.com/rss.xml) [TikTok](https://www.tiktok.com/@storagereview) [![StorageReview.com]()](https://www.storagereview.com) ≡ Menu - [Home](https://www.storagereview.com/) - [Storage Reviews](https://www.storagereview.com/review) - [End User Reviews](https://www.storagereview.com/consumer) - [Enterprise Reviews](https://www.storagereview.com/enterprise) - [Ubiquiti Reviews](https://www.storagereview.com/best/ubiquiti-reviews) - [SR Merch](https://store.storagereview.com) - [Leaderboards](https://www.storagereview.com/best) - [Best Storage Arrays](https://www.storagereview.com/best/storage-arrays) - [Best Enterprise SSDs](https://www.storagereview.com/best/enterprise-ssds) - [Best Servers](https://www.storagereview.com/best/servers) - [Best Enterprise GPUs](https://www.storagereview.com/best/enterprise-gpus) - [Best Desktops for Local AI](https://www.storagereview.com/best/desktops-local-ai) - [Best Laptops for Local AI](https://www.storagereview.com/best/laptops-local-ai) - [Best Local LLM Tools](https://www.storagereview.com/best/local-llm-tools) - [Agentic AI Hardware](https://www.storagereview.com/best/agentic-ai-hardware) - [Best SSDs & Hard Drives](https://www.storagereview.com/best_drives) - [Best Portable SSDs](https://www.storagereview.com/best/portable-ssds) - [Best Business Laptops](https://www.storagereview.com/best/business-laptops) - [Best Mobile Workstations](https://www.storagereview.com/best/mobile-workstations) - [Best Desktop Workstations](https://www.storagereview.com/best/desktop-workstations) - [Best Mini PCs](https://www.storagereview.com/best/mini-pcs) - [Best Laptop Battery Life](https://www.storagereview.com/best/laptop-battery-life) - [Storage Reference Guide](https://www.storagereview.com/storage-reference-guide) - [About SR](https://www.storagereview.com/about-storagereview) - [StorageReview.com Sweepstakes Rules and Regulations](https://www.storagereview.com/storagereview-com-sweepstakes-rules-and-regulations) Search [Home](https://www.storagereview.com/) » What is Direct Attached Storage (DAS)? # What is Direct Attached Storage (DAS)? Direct Attached Storage (DAS), the name is pretty self-explanatory. A disk subsystem that is directly connected to a host rather than going through a switched network, thereby giving the host exclusive access to the disks. The category obviously includes disks internal to a physical server, but in the storage realm we most often think about JBOD (“just a bunch of disks”) shelves attached to a server via SAS cable. Traditionally, JBODs were added to servers to either expand capacity or to deliver higher IOPS through additional spindle count. Modern operating system and application vendors have recently been getting smarter about storage – tuning application performance and building storage logic into the application layer that was previously the realm of the disk array manufacturers. This move has shifted how DAS is positioned and what use cases it is applicable in. ![](https://www.storagereview.com/wp-content/uploads/2012/08/HP-DAS.png)For example, with Microsoft Exchange 2010, the folks in Redmond released the ability to have multiple Exchange Servers, each with DAS replicating to each other through what they call Database Availability Groups (DAGs). Most companies had Exchange traditionally connected to SAN and lots of disks to provide both resiliency and IO. With Exchange 2010, Microsoft improved the IO profile, and, with DAGs are actively positioning DAS as a connectivity option to get large, low-cost mailboxes without sacrificing performance or resiliency. Today’s DAS is also more nuanced than the JBODs of old. ‘Shared DAS’ or ‘Direct Area Networks (DAN)’ are variations on a theme whereby multiple hosts can be connected to a set of array controllers, bypassing the need for a switched infrastructure. On the small side, we have modular arrays that can support 4 servers directly attached in a resilient formation. A nice little array deployment plan for a midmarket cluster at a lot less cost than building up a SAN infrastructure. On the high-end, we have tier 1 disk arrays with massive amounts of host connectivity and emerging converged networking infrastructure that can also bypass multi-layer switches. An example of the latter is the Virtual Connect FlexFabric model within the HP BladeSystem. Using ‘Flat SAN technology,’ you can direct attach over 700 servers to a 3PAR disk array without the need for any SAN switches or host HBAs. Another evolution of DAS is the emergence of independent public cloud providers looking at deploying massive farms of ‘storage servers’ and low-cost JBODs as an alternative to large dedicated disk arrays. Not to be confused with those deploying traditional applications in IT-as-a-Service (ITaaS) paradigms, these independent public cloud providers are bringing completely new applications to market (think Dropbox and the like) and, in order to reach competitive price points, they often pursue homegrown or open-source storage software as a route to pool low-cost, high-capacity disks together in unique ways. The DAS space will be interesting to watch as application vendors continue to build more logic into applications and as traditional array vendors fight for share. This trend benefits the systems vendors that have a strong affiliation with compute infrastructure and DAS, but hurts traditional ‘storage only’ vendors who have made their bread and butter on shared storage infrastructure. **Related Content** - [What are Storage Area Network (SAN) Arrays?](https://www.storagereview.com/what_are_storage_area_network_san_arrays) - [What is Network Attached Storage (NAS)?](https://www.storagereview.com/what_is_network_attached_storage_nas) - [What is Unified Storage?](https://www.storagereview.com/what_is_unified_storage) - [What is Object Storage?](https://www.storagereview.com/what_is_object_storage) **About the Author **![](https://www.storagereview.com/wp-content/uploads/2012/08/Brad-Parks-HP.png)Brad Parks – Converged Infrastructure Strategist,  [HP Storage](http://www8.hp.com/us/en/products/data-storage/overview.html)  Twitter –  [@HPBradParks](https://twitter.com/HPBradParks) Brad Parks is a strategist in HP Enterprise Servers, Storage and Networking, focusing on product and solution development for HP Converged Infrastructure as it relates to HP Storage. Parks works with customers, product teams and the technical community to develop content and programs to communicate HP’s strategic direction and unique customer value related to data storage.   Trusted Vendors Products and solutions from our affiliate partners: - [ ![Ubiquiti Logo]() Ubiquiti ](https://store.ui.com/us/en?a_aid=StorageReview "Opens in a new window") - [ ![Newegg Logo]() Newegg ](https://click.linksynergy.com/fs-bin/click?id=g5terNMDhz0&offerid=1207190.18&subid=0&type=4 "Opens in a new window") - [ ![Amazon Logo]() Amazon ](https://amzn.to/4fLJUEW "Opens in a new window") Newsletter Subscribe to the StorageReview newsletter to stay up to date on the latest news and reviews. We promise no spam! 1 Leave this field empty if you’re human: ## Advertisement Content Categories [Facebook](https://www.facebook.com/@storagereview) [X](https://twitter.com/storagereview) [Instagram](https://www.instagram.com/storagereview/) [LinkedIn](https://www.linkedin.com/company/storagereview-com) [YouTube](https://www.youtube.com/user/storagereview?sub_confirmation=1) [Email](mailto:info@storagereview.com) [Spotify](https://open.spotify.com/show/1y6VnznABhHeOSMOmbDTz0) [Reddit](https://www.reddit.com/r/StorageReview/) [Discord](https://discord.gg/TwMHb4azdC) [RSS](https://www.storagereview.com/rss.xml) [TikTok](https://www.tiktok.com/@storagereview) Copyright © 1998-2025 Flying Pig Ventures, LLC Cincinnati, Ohio. All rights reserved. Manage your privacy To provide the best experiences, we and our partners use technologies like cookies to store and/or access device information. Consenting to these technologies will allow us and our partners to process personal data such as browsing behavior or unique IDs on this site and show (non-) personalized ads. Not consenting or withdrawing consent, may adversely affect certain features and functions. Click below to consent to the above or make granular choices. Your choices will be applied to this site only. You can change your settings at any time, including withdrawing your consent, by using the toggles on the Cookie Policy, or by clicking on the manage consent button at the bottom of the screen. Functional Functional Always active The technical storage or access is strictly necessary for the legitimate purpose of enabling the use of a specific service explicitly requested by the subscriber or user, or for the sole purpose of carrying out the transmission of a communication over an electronic communications network. Preferences Preferences The technical storage or access is necessary for the legitimate purpose of storing preferences that are not requested by the subscriber or user. Statistics Statistics The technical storage or access that is used exclusively for statistical purposes. The technical storage or access that is used exclusively for anonymous statistical purposes. Without a subpoena, voluntary compliance on the part of your Internet Service Provider, or additional records from a third party, information stored or retrieved for this purpose alone cannot usually be used to identify you. Marketing Marketing The technical storage or access is required to create user profiles to send advertising, or to track the user on a website or across several websites for similar marketing purposes. Statistics Marketing Features Always active Special features Special purposes Always active - Manage options - Manage services - Manage {vendor\_count} vendors - [Read more about these purposes](https://cookiedatabase.org/tcf/purposes/) Accept Deny Manage options Save preferences Manage options - {title} - {title} - {title} Manage your privacy To provide the best experiences, we use technologies like cookies to store and/or access device information. Consenting to these technologies will allow us to process data such as browsing behavior or unique IDs on this site. Not consenting or withdrawing consent, may adversely affect certain features and functions. Functional Functional Always active The technical storage or access is strictly necessary for the legitimate purpose of enabling the use of a specific service explicitly requested by the subscriber or user, or for the sole purpose of carrying out the transmission of a communication over an electronic communications network. Preferences Preferences The technical storage or access is necessary for the legitimate purpose of storing preferences that are not requested by the subscriber or user. Statistics Statistics The technical storage or access that is used exclusively for statistical purposes. The technical storage or access that is used exclusively for anonymous statistical purposes. Without a subpoena, voluntary compliance on the part of your Internet Service Provider, or additional records from a third party, information stored or retrieved for this purpose alone cannot usually be used to identify you. Marketing Marketing The technical storage or access is required to create user profiles to send advertising, or to track the user on a website or across several websites for similar marketing purposes. Statistics Marketing Features Always active Special features Special purposes Always active - Manage options - Manage services - Manage {vendor\_count} vendors - [Read more about these purposes](https://cookiedatabase.org/tcf/purposes/) Accept Deny Manage options Save preferences Manage options - {title} - {title} - {title} Manage consent Manage consent ```json {"@context":"https:\/\/schema.org","@graph":[{"@type":"WebPage","@id":"https:\/\/www.storagereview.com\/what-is-direct-attached-storage-das","url":"https:\/\/www.storagereview.com\/what-is-direct-attached-storage-das","name":"What is Direct Attached Storage (DAS)? - StorageReview.com","isPartOf":{"@id":"https:\/\/www.storagereview.com\/#website"},"primaryImageOfPage":{"@id":"https:\/\/www.storagereview.com\/what-is-direct-attached-storage-das#primaryimage"},"image":{"@id":"https:\/\/www.storagereview.com\/what-is-direct-attached-storage-das#primaryimage"},"thumbnailUrl":"https:\/\/www.storagereview.com\/wp-content\/uploads\/2012\/08\/HP-DAS-thumb.png","datePublished":"2012-08-12T19:20:34+00:00","breadcrumb":{"@id":"https:\/\/www.storagereview.com\/what-is-direct-attached-storage-das#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/www.storagereview.com\/what-is-direct-attached-storage-das"]}]},{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/www.storagereview.com\/what-is-direct-attached-storage-das#primaryimage","url":"https:\/\/www.storagereview.com\/wp-content\/uploads\/2012\/08\/HP-DAS-thumb.png","contentUrl":"https:\/\/www.storagereview.com\/wp-content\/uploads\/2012\/08\/HP-DAS-thumb.png","width":100,"height":122},{"@type":"BreadcrumbList","@id":"https:\/\/www.storagereview.com\/what-is-direct-attached-storage-das#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/www.storagereview.com\/"},{"@type":"ListItem","position":2,"name":"What is Direct Attached Storage (DAS)?"}]},{"@type":"WebSite","@id":"https:\/\/www.storagereview.com\/#website","url":"https:\/\/www.storagereview.com\/","name":"StorageReview.com","description":"StorageReview.com is a leading provider of news and reviews throughout the entire IT stack - from the datacenter to the edge, and all points in between.","publisher":{"@id":"https:\/\/www.storagereview.com\/#organization"},"potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/www.storagereview.com\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"en-US"},{"@type":"Organization","@id":"https:\/\/www.storagereview.com\/#organization","name":"StorageReview.com","url":"https:\/\/www.storagereview.com\/","logo":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/www.storagereview.com\/#\/schema\/logo\/image\/","url":"https:\/\/www.storagereview.com\/wp-content\/uploads\/2020\/02\/Storage-Reviews-2-2.png","contentUrl":"https:\/\/www.storagereview.com\/wp-content\/uploads\/2020\/02\/Storage-Reviews-2-2.png","width":344,"height":61,"caption":"StorageReview.com"},"image":{"@id":"https:\/\/www.storagereview.com\/#\/schema\/logo\/image\/"},"sameAs":["https:\/\/x.com\/storagereview","http:\/\/youtube.com\/user\/storagereview"]}]} ```