As it was said, you may try unRAID which would handle even the different size drives.

As alternative, it looks like mdadm should fit your requirements. You can use smth like openmediavault for that.

I would definitely contact seller for that. Warranty is one of the things why you get the new drive, at least that is critical to me. Return the drive if they would refuse to provide you with the warranty.

Good luck further with your configuration!

Well, same I can tell about you.

i don’t have space for disk image by the way.

Get the backup drive for it, make the image and restore after. It’s the most efficient way.

Look for the best deals and the best $/TB ratio. Not really much other advices rather than having more backup copies next time.

It is still not only about me. But ok.

Well, but if that doesn’t happen?

I do prefer pre-built NAS over DIY when it comes for simple and straightforward solution, but it still depends from the use case.

I do not see any issues using not DIY NAS, as OP wants. As you mentioned, it is a data hoarder forum where people can save the data where they want.

Hmm.

But the question was obviously not about DIY NAS… Ok.

Yeah!

But, you still can use smth like Synology cloud sync to synchronize the data on cloud and access them via the internet. For sure, suitable Synology NAS is required.

Depends on the NAS. Some of them offer native cloud option or access via the VPN.