Migrating data from Readynas Ultra 2 from RAIDar 4.2.31 to 6.9.5

Starting:

I've got an amazing NAS from Netgear, being able to scale up since many years:

2x4 TB in RAID 1 (mirroring)  with 2 GB of RAM. Firmware 4.2.31.

It is powerfull, just what I needed. Due to security purposes SMB, etc. with Windows 10 environment, I saw that it is technically possible to upgrade the RAIDar 4.2.31 to the newest OS build 6.9.5. After this migration even being able to upgrade to the newest version.

My main references were those two links:

upgrading-a-legacy-readynas-from-raidiator-4-2-x-to-6-2-x/ 

( ReadyNAS-OS-6-9-3-Run-on-existing-x86-4-2-notsupported )

Procedure:

1) backup file externally (move, not copy)

2) import Add-On: PREP4TOR6_0.1-x86.bin

3) Firmware update: R4toR6_6.9.5.bin

4) restart when requested

5) Bluelight is blinking (=Booting) and the activity LED is also shortly blinking every 20-30 seconds for 5 ms.

Disk 1 and 2 are both green on and stable.

Since almost 3 days now !?

Now, the issue:

 I have restarted the NAS and I have no clue, how long I have to wait, and if the NAS is performing the expected factory default boot !?

I konw that for 2x4 TB it neeeds a lot of patience, but I am disturb not being able to know, if something is really happen or not. Both tools are showing the same information: "Management Service is offline".   

I would be so happy to get some detailed description, what happens through this steps and How I would be able to debug/solve this upgrade without losing my ReadyNAS.

Many thanks to all of you,

Dan

I hope I do not have to downgrade back => Downgrade-to-RAIDiator-x86-from-ReadyNAS-OS-notsupported