Thank you for all the shared information, it was a pleasure reading it and following it side by side. Somehow before receiving the message like ...10 minutes earlier i managed somehow to make it boot & work with DSM 6.1. I made a back-up for the HDD and stick and tried with a new ones the tutorial again following your information. It runs so smoothly but i made the following changes to have a success chance and maybe somewhere i missed something or i encountered a strange behaviour :
0.1) On my first try i was messing up the versions from the main download page, not the secondary one and i was ending with 100+ files without know from where i got it so it would be nice to have somekind of internal file tracking like a blank "1.02b.txt" in the image or the archives name (it's just a nice to have.)
1) Nothing worked until i setup the new extra file in the iso , even if at the start of the process the lan drivers where working correctly, so in both cases (fresh install and updating were altered with the extra file)
2) From the 5.2 jump to 6.1 some files were keept as a migration process but it did slow the device until a mini clean was made in the apps.
3) With the 5.2 jump to 6.1 the interface somehow didnt scale correctly to my resolution (common one : 1920 x 1200 on chrome browser.)
4) With a clean install everything runs let's say more than ok we have some speed but checking the internet for some notes i found out more about the universal search that was causing on some system some delays. After logging with ssh and uprising as root based on tutorials i found the command : synopkg uninstall SynoFinder witch made my dsm 6 even faster than 5.2 and i am amazed by this.
The other strange thing is that my device is getting a new random mac address if i do an update from 5.2 to 6.1 with the same modification in the grub file i think it was called but if i do a fresh install the "correct / real" mac is assigned to the device (this was so strange.)
I will make a further performance test and maybe come back with some data for all the users based on my little pc.
If I may ask you a few more things before "closing the thread" :
a) What if I would buy some cheap 4 quad core intel NUC (never had one before) with some ram to have vm machine or docker on it ? or maybe the question would be what machine in your knowledge has the most gain of performance per power consumption. (for my example and small tests on my DS411j (single core 1.2 / 128 ram) i have a power consumption of 17 W/h, on the DS210J (single core 0.8 / 128 ram) consumption is 12 W/h and now on this laptop is 7 W/h on 1.6ghz with 1024 ram)
b) I didn't had with what to try , but can I make an external usb hdd to be seen as an internal one and create a raid 1 between them ?
c) in the dsm at the info tab you have the cpu temperature . On my DS210j works correctly -> cpu and hdd temps are different , on my ds411j this feature on the cpu is missing. On the mini laptop the cpu temp is stuck at 40c but the temperatures on the hdd is working correctly . Is this something fixable ?
As a final word,
Thank you again for the information and time spent,
Yes, i do like to thinker with things and try new stuff everyday.
Have a nice holiday.