jensmander

The usual ones. Choose your loader (1.03b for DS3615 or DS3617, 1.04b for DS918+), create your boot stick, set up your bare-metal system with usb devices as the primary boot option, plug in your original Synology’s hdds in the new system, start it up and check which IP it received (DHCP needed in LAN). Alternative would be the Synology Assistant. Then connect to your XPenology using your browser. It will offer you migration install (keep all your data, users and apps) or a clean install. Choose the migration and usually it should work after the first reboot.

If all hdds are detected within DSM, yes. 3 drives are the minimum for RAID 5.

No, Hyper-V is not supported.

It‘s only a simple pie chart summary of what each server consumes on disk space within HyperBackup‘s folder (which can be viewed with DSM‘s file explorer).

2-3 Sekunden wohl eher aus dem Standby, kein richtiger cold boot. Sobald man konventionelle HDDs in einem System hat, ist die response time meist immer um einiges höher, da die erst ihren spin-up fahren müssen. Betreffend XPEnology und boot time: ja, wenn man nur SSDs verwendet geht es etwas schneller. Den timeout im Loader kannst du von 3 Sekunden (default) auf 1 Sekunde heruntersetzen, aber ob das nun der absolute Bringer ist... Wie Du die grub.cfg nachträglich bearbeiten bzw. den stick mounten kannst, ist hier beschrieben:

Yes, in basic it‘s the correct way. You’ll have to reinstall DSM, install HyperBackup and restore everything with this app. Beside HyperBackup I would also make a backup from the DSM configuration from time to time.

Next time be sure to read the forum rules. I moved your topic to general questions, this has nothing to do with tutorials and guides.

Wrong forum section and you should be more specific in your question. I think you mean the use of Let‘s Encrypt (which is possible). Regarding the loader more informations are needed (mainboard, cpu, nic, etc.).

For a R/W cache it‘s advisable to use two SSDs of the same size and model. But as @flyridesaid, the usual risks should be considered.

The stick is only needed for the boot process and is not monitored. When the stick gets hot this means your mainboard is not well cooled and you should check your case, especially the cpu cooler and fan. If the cpu fan doesn’t work properly the heat is not blown away and concentraded around the socket. Usually systems shut down on temperatures above 90 degrees celsius, this would explain the improper shutdown.

Solange die NAS nicht von außen erreichbar ist (Sicherheitsupdates) und keine Pakete meckern (bspw. Plex), sind die Updates kein Zwang.

Did you modify this entry in the grub.cfg, maybe an unwanted line break or typo? Did you compare the appropiate line with the original grub.cfg? Any difference?

Of course you can run this on original Synologys or even XPenologys. It’s a RAM test which can take many hours to complete. But for bare-metal XPenologys I would prefer the classic way with bootable tools like MemTest+ or anything similar.

Wenn der B120i controller verbaut ist, muss bzw. sollte dieser auf AHCI im Bios umgestellt werden. Nicht den controller komplett deaktivieren.

You could use a VPN solution or open the corresponding ports (NAT) on your firewall to your XPenology box in combination with a DDNS. Usually this would be 5000 (HTTP) or 5001 (HTTPS). But opening these ports is risky and should go along with additional security measurements.