Hallo Leute,
ich hatte neulich das Problem mit einer DS412+, die mit DSM 6.0 vorinstalliert bei mir ankam. Mit dem folgenden Howto konnte ich sie auf DSM 5.2 zurücksetzen. Ich hoffe es hilft auch in Eurem Fall! Bitte achtet darauf, die für Euch entsprechenden DSM-Versionen da zu haben.
I figured out a way. Where version file editing doesn't work. Follow the video or the guide below at your own risk. View it from a pc to see the notes. INTEL based synology devices. (GRUB only, not marvell uboot)
https://youtu.be/DFtOmEv63n4
You will need the 5644 and 5967 pat files for your device.
http://usdl.synology.com/download/DSM/release/5.2/5644/
http://usdl.synology.com/download/DSM/release/5.2/5967/Also you will need 7zip
http://www.7-zip.org/a/7z1602.exe
and lastly, putty.
https://the.earth.li/~sgtatham/putty/latest/x86/putty.exe
1. Turn on synology and backup data if needed.
2. Create a shared folder. ("test" is used in this guide)
3. Using 7zip, extract 4 files from DSM 5644.pat (grub_cksum.syno, rd.gz, zImage, checksum.syno) and place the files in the newly created shared folder on the NAS.
4. Enable telnet in the DSM control panel.
5. Using putty, or another telnet client, access the diskstation.
6. Log in as admin.
7. Type "sudo su". The password it asks for will also be the admins password.
8. Type "cd /dev" to change to the devices directory.
9. Type "ls" to view all devices. Scroll up through the list to make sure synoboot2 is listed. If it's not, I wouldn't proceed.
10. Type "mkdir /mnt/synoboot" to make a directory to mount to.
11. Type "mount synoboot2 /mnt/synoboot" to mount the boot files to the directory we created.
12. Type "cd /mnt/synoboot" to change to that directory.
13. Type "ls" to view the files in the directory. (note that the names of the 4 files we put in the shared folder, should be there. Although these ones listed are the DSM6 versions)
14. Type "cp /volume1/test/checksum.syno /mnt/synoboot" to overwrite the DSM6 file with the DSM5.2 file from the "test" shared folder.
15. Type "cp /volume1/test/grub_cksum.syno /mnt/synoboot" to overwrite the DSM6 file with the DSM5.2 file from the "test" shared folder.
16. Type "cp /volume1/test/rd.gz /mnt/synoboot" to overwrite the DSM6 file with the DSM5.2 file from the "test" shared folder.
17. Type "cp /volume1/test/zImage /mnt/synoboot" to overwrite the DSM6 file with the DSM5.2 file from the "test" shared folder.
18. Go back into the DSM interface and shutdown. Once the device is shutdown, remove the disks. (This step is important because if you do not remove the disks, the next powerup will detect an issue and recover the DSM6 boot image) [Suggestion from WiseOwlFinds: Make sure to also eject and disconnect your USB external hard drives as well. Forgetting to do so, could cause that your DiskStation from not being able to detect that particular USB hard drive after the re-installation of DSM]
19. Power the device up and find it. Should say no disks inserted. Before clicking the connect again button, put the hard disks back in and wait for the HDD LED's to light up.
20. If disks are in, click the connect again button. Next page should come up saying to reinstall DSM. Make sure to choose the 5967 pat file so that the bootimage is overwritten correctly.
21. Good to go! Data should remain intact as long as it is in a shared folder, and DSM should be a completely stock 5.2 - 5967.
Viel Glück!