I own several external 2.5’’ HDDs on the 1 TB range where I save my data. Samsung has worked well for me, but now I need more space.
One option would be to buy an external SSD instead of HDD.
Another would be to get an external NVME, but so far I haven’t found cases for them.
Nowadays we even have 1 TB flash drives, should I get one of these instead?
I could also buy 2 0.5 TB micro SD cards instead.
So many options make it difficult to decide.
What brands and technologies do you recommend?
Software is going to be debian based.
Do you have any extreme conditions that may affect your cluster?
If everything is standard, just go mid to low grade and raid it. If heat, radiation, reliability, or energy usage are funded concerns, then the answer changes.