Upgrade synology DS409 to DSM6

I have bought an DS409 a few years ago and I felt quite disappointed not to get every update brought by DSM 5 then 6.

One easy solution would be to buy a new NAS but, to be honnest, my current one is still working fine (and I have modified it a lot).

Goal of this post will be to show how to upgrade and as well, what is the process to understand if you can upgrade.

First, you need to know what is the CPU of your NAS to install a compatible DSM, one excellent resource:


also available here if the first source stop working:


For my NAS, I found that it embed a 88f6281 (DS409 – synology_88f6281_409) and wonderful information, a newer version of the 4 slot NAS embed the same CPU (DS411j – synology_88f6281_411j).

So the solution will be to trick my NAS to believe it is a DS411j instead of a DS409.

DSM rely on the file /etc.defaults/synoinfo.conf to recognize the NAS model it is.

In these file, I have replace the model reference in the unique line:




you then just save the file, connect to the web interface and launch the update process, it will then propose to migrate to DSM V5.

In order to reach DSM V6 you will have to go through a few updates, there are milestones version you cannot skip apparently.

For the upgrade to DSM 5.2.5565, I have encountered an error while going through the installation, the solution was to provide manually the pat file of the update.

All DSM releases are available here:


you just need to download the right file, in my case it was:


Since then, I am using DSM 6.0 with no regression for my usage.

Known issues are:

  • found on forum: esata not working directly

    in /etc.defaults/synoinfo.conf

    Add supportESATA="yes"under the line: support_s2s=”yes”

    alter the line esataportcfg=”0x0″ to esataportcfg="0x10"

  • If you were connecting on SSH using root account (boooh) it will not work anymore, you should connect with your admin account you are using to connect to the webinterface (and sudo will do the rest)


if I find any other issues or tips and tricks it will be added here.


Posted in Hacks
8 comments on “Upgrade synology DS409 to DSM6
  1. John says:

    So now that it’s been a while, how has this held up? I’m considering it for my DS409. Did you add additional RAM? If not, did that affect performance at all?

    • HackGins says:

      The NAS is still working fine and I haven’t encountered any issue since the upgrade.
      I continue to receive the DSM update (current version is Version: 6.2-23739-2 (2018-07-12)).
      I have not added any additional RAM and didn’t see any performance impact at first.
      Now, I start to have some performance issue (linked mostly with nodejs server and latest java version), it is mostly visible when I use the web interface, it is slower than before but no impact on network transfer speed, only the web interface is slower.

  2. Gunter says:

    Hi there,

    discovered your post yesterday and tried it on my DS209 which was stuck with DSM 4.22
    Upgraded to DSM 6.2.1-23824 Update 6 now by telling my DS209 it’s a DS212j. So far I see no issues – as written before the CPU goes more towards 100% than before which should be related due to the heavy HTML5 UI. I’ll try out more in the next days!

    Anyway, thanks a bunch, no need to buy a new Diskstation!

    • Mike says:

      How did you manage to upgrade the 209? Mine doesn’t see any updates when I change the model number in the syncinfo.conf. It still sees it as a DS209j and if I reboot after changing this I need to reinstall DSM 4.22

      • HackGins says:

        Depend on your NAS model,
        if your nas is a DS209J then the CPU is a ppc824x, no model later received this CPU so there is no DSM package update possible.
        if it is a DS209 then the CPU is a 88f6281 onboarded as well on DS210j, DS211j and DS212j and it should work as described in the article.

  3. Peter says:

    This Idea sounds very good. I do have a 409+, do you think this hack would work with a 409+, too?

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