--- title: this file is FAKE in Linux | daily.dev description: A demonstration shows how Linux can create a 1TB file that reports as 1.1 terabytes in size but consumes zero bytes of actual disk space, despite only 699GB... canonical: https://daily.dev/posts/this-file-is-fake-in-linux-7wspzsxws twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: this file is FAKE in Linux | daily.dev og:description: A demonstration shows how Linux can create a 1TB file that reports as 1.1 terabytes in size but consumes zero bytes of actual disk space, despite only 699GB... og:url: https://daily.dev/posts/this-file-is-fake-in-linux-7wspzsxws og:image: https://api.daily.dev/og/posts/7wSpZsxwS.png og:image:alt: this file is FAKE in Linux og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # this file is FAKE in Linux **[typecraft](https://daily.dev/sources/typecraft)** · 1 min read · 0 upvotes · 0 comments ## Summary A demonstration shows how Linux can create a 1TB file that reports as 1.1 terabytes in size but consumes zero bytes of actual disk space, despite only 699GB being available. This is possible because of sparse files, where Linux tracks a file's logical size without allocating physical storage for unwritten regions called holes. Reading from these holes returns zeros. The main practical use case highlighted is virtual machine disk images, which can be allocated a large maximum size upfront while only consuming disk space as data is actually written. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Questions this post answers ### Why does a 1TB file on Linux not actually use any disk space? It is a sparse file, a Linux filesystem feature that tracks a file's logical size separately from the physical disk blocks actually allocated to it. Unwritten regions, called holes, take up zero bytes on disk even though the file reports its full logical size, such as 1.1 terabytes. Reading from a hole returns zeros instead of real stored data. _When you're debugging disk usage mysteries like sparse files, daily.dev surfaces the systems explainers that make it click._ ### What is a practical use case for sparse files in Linux? Virtual machine disk images commonly use sparse files, letting you allocate a large maximum size such as a virtual hard drive upfront without immediately consuming that much physical disk space. As the VM writes more data over time, Linux allocates real disk blocks only for the parts actually written, growing physical usage gradually alongside the virtual drive. _Anyone provisioning VM storage efficiently can find more filesystem deep dives like this through daily.dev._ ## Similar posts on daily.dev - [Creating massively huge fake files and binaries](https://daily.dev/posts/creating-massively-huge-fake-files-and-binaries-h1cmc1cod) · Farid Zakaria’s Blog · 0 upvotes · 0 comments - [There was 100GB on my Linux data drive I wasn't allowed to use, and one command released it](https://daily.dev/posts/there-was-100gb-on-my-linux-data-drive-i-wasn-t-allowed-to-use-and-one-command-released-it-lv43sfrje) · XDA Developers · 0 upvotes · 0 comments - [The hole in my falloaction](https://daily.dev/posts/the-hole-in-my-falloaction-0mp20s5mq) · Ayende @ Rahien · 0 upvotes · 0 comments - [When the Pieces Don’t Add Up: The Mystery of the Full File System](https://daily.dev/posts/when-the-pieces-don-t-add-up-the-mystery-of-the-full-file-system-emgl6c1v7) · Simple Thread · 0 upvotes · 0 comments --- Tags: [#linux](https://daily.dev/tags/linux), [#infrastructure](https://daily.dev/tags/infrastructure), [#filesystems](https://daily.dev/tags/filesystems) [View this post on daily.dev](https://daily.dev/posts/this-file-is-fake-in-linux-7wspzsxws) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"this file is FAKE in Linux","url":"https://daily.dev/posts/this-file-is-fake-in-linux-7wspzsxws","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/this-file-is-fake-in-linux-7wspzsxws"},"datePublished":"2026-09-29T21:12:54.874Z","dateModified":"2026-09-29T21:13:25.989Z","description":"A demonstration shows how Linux can create a 1TB file that reports as 1.1 terabytes in size but consumes zero bytes of actual disk space, despite only 699GB...","image":"https://i.ytimg.com/vi/DrtF_z9AYCA/sddefault.jpg","thumbnailUrl":"https://i.ytimg.com/vi/DrtF_z9AYCA/sddefault.jpg","isAccessibleForFree":true,"articleSection":"typecraft","inLanguage":"en","publisher":{"@type":"Organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180}},"author":{"@type":"Organization","name":"typecraft","logo":"https://media.daily.dev/image/upload/s--iVakgkBx--/f_auto/v1728807219/logos/typecraft","url":"https://daily.dev/sources/typecraft"},"commentCount":0,"discussionUrl":"https://daily.dev/posts/this-file-is-fake-in-linux-7wspzsxws","interactionStatistic":[{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":0},{"@type":"InteractionCounter","interactionType":{"@type":"CommentAction"},"userInteractionCount":0}],"keywords":"linux,infrastructure,filesystems","timeRequired":"PT1M","video":{"@type":"VideoObject","name":"this file is FAKE in Linux","description":"A demonstration shows how Linux can create a 1TB file that reports as 1.1 terabytes in size but consumes zero bytes of actual disk space, despite only 699GB...","thumbnailUrl":"https://i.ytimg.com/vi/DrtF_z9AYCA/sddefault.jpg","uploadDate":"2026-09-29T21:12:54.874Z","duration":"PT1M","url":"https://api.daily.dev/r/7wSpZsxwS","embedUrl":"https://www.youtube.com/embed/DrtF_z9AYCA"}} {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://daily.dev"},{"@type":"ListItem","position":2,"name":"typecraft","item":"https://daily.dev/sources/typecraft"},{"@type":"ListItem","position":3,"name":"this file is FAKE in Linux"}]} {"@context":"https://schema.org","@type":"FAQPage","@id":"https://daily.dev/posts/this-file-is-fake-in-linux-7wspzsxws#faq","mainEntity":[{"@type":"Question","name":"Why does a 1TB file on Linux not actually use any disk space?","acceptedAnswer":{"@type":"Answer","text":"It is a sparse file, a Linux filesystem feature that tracks a file's logical size separately from the physical disk blocks actually allocated to it. 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