--- title: Improving the reliability of file system monitoring tools description: Linux lacked a reliable real-time interface for notifying applications about file system errors. Existing approaches — watching kernel logs or polling sysfs... canonical: https://daily.dev/posts/improving-the-reliability-of-file-system-monitoring-tools-7kvfsei7d twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Improving the reliability of file system monitoring tools | daily.dev og:description: Linux lacked a reliable real-time interface for notifying applications about file system errors. Existing approaches — watching kernel logs or polling sysfs... og:url: https://daily.dev/posts/improving-the-reliability-of-file-system-monitoring-tools-7kvfsei7d og:image: https://api.daily.dev/og/posts/7kvFSEi7D.png og:image:alt: Improving the reliability of file system monitoring tools 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. # Improving the reliability of file system monitoring tools **[Collabora Blog](https://daily.dev/sources/collabora)** · 5 min read · 0 upvotes · 0 comments ## Summary Linux lacked a reliable real-time interface for notifying applications about file system errors. Existing approaches — watching kernel logs or polling sysfs files — were fragile and could miss events. A new kernel feature, FAN_FS_ERROR, was developed and merged in Linux 5.16. It extends the fanotify interface with a dedicated event queue for file system errors, ensuring listeners always receive notifications even under low-memory conditions. This enables monitoring daemons and sysadmins to be alerted immediately when errors occur, allowing faster recovery actions like rebuilding RAID arrays or running fsck. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Questions this post answers ### What is FAN_FS_ERROR in Linux and what kernel version introduced it? FAN_FS_ERROR is a new fanotify event type that notifies listener applications in real time whenever a file system error is detected. It was merged in Linux kernel 5.16. Unlike previous approaches — polling kernel logs or sysfs files — it uses a dedicated per-listener event queue, guarantees memory availability for reporting even under low-memory conditions, and prevents events from being overwritten by subsequent errors. _Engineers monitoring storage health in production track kernel additions like this on daily.dev._ ### Why is watching kernel logs not a reliable way to monitor file system errors on Linux? Kernel log monitoring is unreliable for file system error detection because newer log messages can overwrite older ones before a monitoring tool reads them, causing notifications to be lost. Similarly, polling file-system-specific sysfs files that record the last error is a polling mechanism subject to missing intermediate error events. Both approaches lack guaranteed delivery to the listener application. _Teams building resilient storage infrastructure keep up with Linux kernel changes like these on daily.dev._ ## Similar posts on daily.dev - [F2FS Preparing FSERROR Reporting Support](https://daily.dev/posts/f2fs-preparing-fserror-reporting-support-t1fsagxb0) · Phoronix · 0 upvotes · 0 comments - [Linux 7.0 VFS Changes: Non-Blocking Timestamps, Standardized Generic I/O Error Reporting](https://daily.dev/posts/linux-7-0-vfs-changes-non-blocking-timestamps-standardized-generic-i-o-error-reporting-8hdxc0tit) · Phoronix · 0 upvotes · 0 comments - [F2FS Integrates FSERROR Reporting, Reduces Memory Footprint In Linux 7.2](https://daily.dev/posts/f2fs-integrates-fserror-reporting-reduces-memory-footprint-in-linux-7-2-iz9sxnfev) · Phoronix · 0 upvotes · 0 comments --- Tags: [#linux](https://daily.dev/tags/linux) [View this post on daily.dev](https://daily.dev/posts/improving-the-reliability-of-file-system-monitoring-tools-7kvfsei7d) ```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":"Improving the reliability of file system monitoring tools","url":"https://daily.dev/posts/improving-the-reliability-of-file-system-monitoring-tools-7kvfsei7d","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/improving-the-reliability-of-file-system-monitoring-tools-7kvfsei7d"},"datePublished":"2026-08-11T08:56:27.355Z","dateModified":"2026-08-11T09:42:42.131Z","description":"Linux lacked a reliable real-time interface for notifying applications about file system errors. 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It was merged in Linux kernel 5.16. Unlike previous approaches — polling kernel logs or sysfs files — it uses a dedicated per-listener event queue, guarantees memory availability for reporting even under low-memory conditions, and prevents events from being overwritten by subsequent errors. Engineers monitoring storage health in production track kernel additions like this on daily.dev."}},{"@type":"Question","name":"Why is watching kernel logs not a reliable way to monitor file system errors on Linux?","acceptedAnswer":{"@type":"Answer","text":"Kernel log monitoring is unreliable for file system error detection because newer log messages can overwrite older ones before a monitoring tool reads them, causing notifications to be lost. Similarly, polling file-system-specific sysfs files that record the last error is a polling mechanism subject to missing intermediate error events. Both approaches lack guaranteed delivery to the listener application. Teams building resilient storage infrastructure keep up with Linux kernel changes like these on daily.dev."}}]} ```