--- title: Ceph In Linux 7.4 Adds Global Mount Option For Lazy I/O description: Linux 7.4 adds a global 'lazyio' mount option for the Ceph filesystem client. It enables lazy I/O for all regular files at open time, allowing buffered I/O... canonical: https://daily.dev/posts/ceph-in-linux-7-4-adds-global-mount-option-for-lazy-i-o-mdio1aznj twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Ceph In Linux 7.4 Adds Global Mount Option For Lazy I/O | daily.dev og:description: Linux 7.4 adds a global 'lazyio' mount option for the Ceph filesystem client. It enables lazy I/O for all regular files at open time, allowing buffered I/O... og:url: https://daily.dev/posts/ceph-in-linux-7-4-adds-global-mount-option-for-lazy-i-o-mdio1aznj og:image: https://api.daily.dev/og/posts/mDiO1azNJ.png og:image:alt: Ceph In Linux 7.4 Adds Global Mount Option For Lazy I/O 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. # Ceph In Linux 7.4 Adds Global Mount Option For Lazy I/O **[Phoronix](https://daily.dev/sources/phoronix)** · 2 min read · 0 upvotes · 0 comments ## Summary Linux 7.4 adds a global 'lazyio' mount option for the Ceph filesystem client. It enables lazy I/O for all regular files at open time, allowing buffered I/O through the page cache even when multiple clients have a file open for write. This relaxed cache coherency mode targets HPC-style workloads. Separately, the inline data feature, experimental and deprecated since 2020, is being removed, and Linux 7.4 adds a CEPH_FS_INLINE_DATA Kconfig option that defaults to off; inline data was added in Linux 3.19 in 2014. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Questions this post answers ### What does the new lazyio mount option do in the Ceph kernel client for Linux 7.4? It enables lazy I/O globally for all regular Ceph files at open time, instead of requiring a per-file ioctl. Lazy I/O allows buffered I/O through the page cache even when multiple clients have the same file open for write, trading cache coherency for performance in workloads like HPC that can tolerate it. _Teams tuning Ceph for HPC workloads can track kernel changes like this one on daily.dev._ ### Is Ceph inline data support being removed from the Linux kernel? It is being phased out rather than removed immediately. Linux 7.4 adds a CEPH_FS_INLINE_DATA Kconfig option that defaults to off, so anyone still using inline data (added in Linux 3.19 in 2014, deprecated since 2020) must explicitly set CEPH_FS_INLINE_DATA=Y to keep it working, ahead of a future full removal. _Admins relying on deprecated Ceph features can follow kernel deprecation timelines on daily.dev before they break builds._ ## Similar posts on daily.dev - [Linux 7.3 Adds RWF\_DONTCACHE Support For Block Devices](https://daily.dev/posts/linux-7-3-adds-rwf-dontcache-support-for-block-devices-7dbwfssud) · Phoronix · 1 upvotes · 0 comments - [EXT4 In Linux 7.0 Improves Write Performance For Concurrent Direct I/O Writes](https://daily.dev/posts/ext4-in-linux-7-0-improves-write-performance-for-concurrent-direct-i-o-writes-z5kk6zl4o) · Phoronix · 0 upvotes · 0 comments - [Linux 7.4 Introduces DMA-BUF Support To I/O Path With IO\_uring](https://daily.dev/posts/linux-7-4-introduces-dma-buf-support-to-i-o-path-with-io-uring-qqaosrjkn) · Phoronix · 0 upvotes · 0 comments --- Tags: [#open-source](https://daily.dev/tags/open-source), [#linux](https://daily.dev/tags/linux), [#filesystems](https://daily.dev/tags/filesystems) [View this post on daily.dev](https://daily.dev/posts/ceph-in-linux-7-4-adds-global-mount-option-for-lazy-i-o-mdio1aznj) ```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":"Ceph In Linux 7.4 Adds Global Mount Option For Lazy I/O","url":"https://daily.dev/posts/ceph-in-linux-7-4-adds-global-mount-option-for-lazy-i-o-mdio1aznj","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/ceph-in-linux-7-4-adds-global-mount-option-for-lazy-i-o-mdio1aznj"},"datePublished":"2026-10-31T10:34:40.627Z","dateModified":"2026-10-31T10:37:20.183Z","description":"Linux 7.4 adds a global 'lazyio' mount option for the Ceph filesystem client. 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