I have now finished to move the server to the new provider. I will be busy in the coming days to properly setup all the other stuff that is on the server, email accounts migration etc. After that I will be able to care about the shop manager and other stuff that is not finished right now.
We have now much more RAM and processing power as described before. I will see what I can do to use this optimally for the server. There is a potential that we can increase mob spawning rates and other things. I will try to dial the limits up over the coming days and see how that affects server performance.
I also re-setup the off-site backup now and made sure that we back up the databases and the files once a day. On top of that, the new server has RAID 1 dual HDs for the SSD and the normal HD on the server. Since the server is located on the SSD and I make a mirror on the HD, we have now 5 different places where the data is stored. So unless a meteorite hits somewhere or I do something incredibly stupid, we should be good :)
FYI, what happened on the previous server. At the time, I had a free account for the off-site backup which had limited storage space. I made the decision at the time to only store the weekly backups of the files offline since they take a lot of space. In the meantime I bought an account for the offsite backup for private reasons (to have a backup of my photos) and therefore now also have enough space for the daily files of the minecraft server. What happened on the old server was most likely a defect HD controller. Still now, after I got new HDs, there are still issues. Since the provider has a policy to replace both HDs in case one fails, the main HD was ruined when he connected it to the external connector. The fact that they did not give me a complete new server when I negotiated for a new 2 year lease, was the trigger for me to look for an alternative provider, luckily I found one.