Synology DSM: six current versions at once — and why your DiskStation sees a different update

Six DSM builds currently head their own line in Synology’s archive — from 7.4.1-90080 down to 6.2.4-25556-8. Which one your DiskStation treats as the current one is not decided by the calendar. It is decided by the model number on the front of the box.

Six heads, two branches that still get fixes

The Synology download archive holds every DSM image ever published. Read only the top build of each minor line and you get this, as of 19/08/2026:

Dates from Synology’s Software Life Cycle Policy, document dated 3 July 2026. Four of the six lines are past every phase they had; only 7.4 and 7.3 can still receive anything. And that is narrower than it looks: maintenance brings the security fixes Synology itself rates critical plus selected urgent bug fixes, while the extended life phase brings the critical security fixes and nothing else. The LTS line 7.3, usually read as “supported until October 2028”, is two years of maintenance to October 2027 followed by one year of emergency care.

What the number says

DSM follows MAJOR.MINOR.MICRO-BUILD-NANO. On 7.3.2-86009-4 that reads major 7, minor 3, micro 2, build 86009, nano 4 — and the nano is what Synology spells out as “Update 4”: its own release notes list that same build as 7.3.2-86009 Update 4. Micro releases arrive quarterly and may still carry features; nano releases are incident-driven, carry none, and are held to very strict criteria. The load-bearing sentence in the policy is a different one, though: each minor version of DSM counts as a separate product with its own life-cycle phases. 7.3 and 7.4 are not two states of one system with one end date. Moving between them is a product change, not an update.

Why your DiskStation sees a different update

Rollout is staged. Synology marks releases in the release notes with a note that the version is released in a staged rollout, and the note for DSM 7.4.1-90080 (23 July 2026) carries it. The image sits in the Download Center on day one; the offer inside Control Panel arrives later, and not on the same day for every unit.

Some models are excluded outright. The release note for DSM 7.4-90075 (16 June 2026) lists 48 models and states they will not receive the update on the device and will remain on their most suitable version, that the patch can only be fetched from the Download Center, and that no notification appears in DSM. Not delayed — not offered. The note for DSM 7.3-81180 (8 October 2025) uses the same wording with its own list of 48.

For some models the branch is the terminus. Underneath that list, the 7.4-90075 note prints a second one: for those 58 models, running across the FS, XS, Plus, Value and J series, DSM 7.4 will be the last upgradable version. Even the extended phase follows the hardware: the policy grants DSM 7.1 an extension to June 2025, then footnotes the 42 models it applied to.

What to check on the box

• The installed state.Control Panel → Update shows the running version. It is also where a manual update from a downloaded .pat file runs — the route the release notes send excluded models down.
• The same thing over SSH. cat /etc.defaults/VERSIONprints the fields the interface assembles — productversion, buildnumber, and smallfixnumber for the nano, shown as “Update N” once it is above zero (example).
• The release notes for your model. The release notes page takes a model parameter. Narrowed that way it shows only the builds ever published for your unit — with the exclusion lists and the last-upgradable line wherever they name your unit.

And one reading habit is worth changing. The message that your DSM is up to date does not mean you run the newest DSM. It means nothing is currently being offered to this model. Those are different sentences, and only one of them is on screen.

Occasionally checking is not a procedure

All of it moves: branch heads shift, staged rollouts complete, model lists grow with every release note, end dates get pushed by the vendor. patchletter follows DSM releases on the Synology DSM product page — tick the product and an email arrives when a new version ships; free, no account, one-click unsubscribe. The 13 recorded support cycles, the six branches above included, are on the same page, and what is running out elsewhere in your estate is on the end-of-life overview.

The honest limitation

The dates are soft by declaration — Synology writes that all future life-cycle dates are close approximations, non-definitive and subject to extension. And the harder boundary: patchletter tracks DSM as one product, not as a fleet of models. It can tell you a new DSM build has shipped. It cannot tell you whether your DS220+ will be offered it, whether it sits on an exclusion list, or whether its branch ended years ago. Nothing outside Synology can — that answer lives in the model-specific release note and in the Control Panel of the unit. patchletter also reports new releases, not support endings: the cycles are there to read, but no alarm goes off.

Cycle count from our own dataset, as of 19/08/2026 — 13 DSM cycles. The six top builds come from the Synology download archive; version scheme, phase definitions, end dates and the DSM 7.1 model footnote from Synology’s Software Life Cycle Policy (document dated 3 July 2026); model lists and wording from Synology’s DSM release notes (builds 7.4.1-90080, 7.4-90075 and 7.3-81180). All pages retrieved on 19/08/2026. The release note for your own model remains authoritative.