--- title: v21.2.0 Umbrella released | daily.dev description: Ceph Umbrella, the 21st stable release, is now available and recommended for all users. Container images now run on Rocky Linux 10 (el10), requiring CPUs with... canonical: https://daily.dev/posts/v21-2-0-umbrella-released-dm0bbhs4c twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: v21.2.0 Umbrella released | daily.dev og:description: Ceph Umbrella, the 21st stable release, is now available and recommended for all users. Container images now run on Rocky Linux 10 (el10), requiring CPUs with... og:url: https://daily.dev/posts/v21-2-0-umbrella-released-dm0bbhs4c og:image: https://api.daily.dev/og/posts/Dm0bbhs4C.png og:image:alt: v21.2.0 Umbrella released 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. # v21.2.0 Umbrella released **[Ceph](https://daily.dev/sources/ceph)** · 196 min read · 0 upvotes · 0 comments ## Summary Ceph Umbrella, the 21st stable release, is now available and recommended for all users. Container images now run on Rocky Linux 10 (el10), requiring CPUs with x86-64-v3 support, and cephadm now needs Python 3.9 or newer on every host. The release adds a new 'Fast' erasure coding I/O path with direct reads and CRC checking, and hardens CephX authentication with a new AES256KRB5 cipher plus fixes for CVE-2025-30156 and three 2026 CVEs. The PG autoscaler's default targets rise from 100 to 200 PGs per OSD. The dashboard migrates to the IBM Carbon design system and upgrades Angular to v19. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Questions this post answers ### What CPU requirement does Ceph Umbrella's container images impose? Ceph Umbrella container images are based on Rocky Linux 10 (el10), which requires a CPU supporting the x86-64-v3 microarchitecture level. Deployments on hosts with older CPUs will not be able to run the containerized daemons. Python 3.9 or newer is also required on all hosts for cephadm support. _Teams planning a Ceph upgrade can track hardware and dependency requirements like this on daily.dev._ ### What CVEs does Ceph v21.2.0 Umbrella fix in CephX authentication? Ceph Umbrella fixes CVE-2025-30156, an AES-CBC misuse bug enabling authentication bypass, along with CVE-2026-39944, CVE-2026-50152, and CVE-2026-54330. The release also hardens CephX with a new AES256KRB5 cipher replacing weaker legacy key types as the default, plus online key rotation for mon, OSD, and MDS daemons during upgrades. _Admins patching storage clusters against CVEs can keep tabs on fixes like these via daily.dev._ ### What changed in the PG autoscaler defaults in Ceph Umbrella? The default mon_target_pg_per_osd increased from 100 to 200, and mon_max_pg_per_osd increased from 250 to 500, letting the autoscaler compute more parallelism-friendly pg_num values. Existing pools may autoscale to more PGs after upgrading as a result, and pg_autoscale_during_upgrade paces that splitting so it doesn't disrupt the upgrade itself. _Operators tuning placement groups before a cluster upgrade can follow changes like this on daily.dev._ ## Similar posts on daily.dev - [Ceph.io — v19.2.7 Squid released](https://daily.dev/posts/ceph-io-v19-2-7-squid-released-jbhxkebxr) · Ceph · 0 upvotes · 0 comments - [Get ready for Ansible Automation Platform 2.7](https://daily.dev/posts/get-ready-for-ansible-automation-platform-2-7-hbwgdumti) · Red Hat Developer · 0 upvotes · 0 comments - [Ceph.io — \[CVE\] \[URGENT\] Squid v19.2.6 and Tentacle v20.2.4 released](https://daily.dev/posts/ceph-io-cve-urgent-squid-v19-2-6-and-tentacle-v20-2-4-released-bzynabdep) · Ceph · 5 upvotes · 0 comments --- [View this post on daily.dev](https://daily.dev/posts/v21-2-0-umbrella-released-dm0bbhs4c) ```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":"v21.2.0 Umbrella released","url":"https://daily.dev/posts/v21-2-0-umbrella-released-dm0bbhs4c","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/v21-2-0-umbrella-released-dm0bbhs4c"},"datePublished":"2026-10-28T13:43:14.604Z","dateModified":"2026-10-28T15:02:59.728Z","description":"Ceph Umbrella, the 21st stable release, is now available and recommended for all users. 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