Downgrade Synology DSM

After finishing Prerequisite Before you Install ZurmoCRM on Synology NAS running DSM 5.0, I want to roll back to Synology DSM 4.3 on my DS214SE. But it’s not just manually upload firmware and downgrade, you need to manually modify VERSION file.

Get the Latest DSM 4.3

You may download the latest DSM 4.3 from Index of /download/DSM/4.3. The file name should match your model number. The file I should download is DSM_DS214se_3827.pat instead of DSM_EDS14_4244.pat for my DS214SE. DSM_EDS14_4244.pat is for EDS14 only. It is not compatible with DS214SE.

Edit VERSION File before Upload

First, you need to manually edit /etc.defaults/VERSION to prior than the firmware you want to downgrade. I want to downgrade to DSM 4.3 3827 and change the configuration as below:

majorversion="4"
minorversion="0"
buildphase="hotfix"
buildnumber="3826"
smallfixnumber="0"
builddate="2013/04/18"

Downgrade

Now, you may use Control Panel→System→Update and Restore→DSM Update→Manual DSM Update to upload your firmware and downgrade.

Other Thoughts

Downgrade won’t remove your existing contents but you might have problems to access. I choose to wipe out my storage and use more common standard RAID 1 instead of the special Synology Hybrid RAID. You may use Storage Manager to rebuild.

More method to downgrade may be found in Synology: Wiki: How to reinstall current or previous firmware.

Reference

1. Prerequisite Before you Install ZurmoCRM on Synology NAS running DSM 5.0
2. Synology: DS214
3. Synology: DS214SE
4. Synology: DSM
5. Synology: EDS14
6. Synology: How to choose between different RAID?: 2. Synology Hybrid RAID (SHR)
7. Synology: Index of /download/DSM/4.3
8. Synology: Wiki: How to reinstall current or previous firmware
9. Wiki: Standard RAID levels: RAID 1