Thank you, but what i have read is that SSD is not so smart to use for longterm storage. Bette to have mechanic disks.
I orderd a Toshiba canvio advanced 1TB.
I think this is a matter of over reading and over thinking too much. While this might have been true during the early development stages of SSD, I haven't heard anyone say that modern SSDs are unstable over a few years... the jury is still out over a few decades. So sure if the intent is to copy something and lock it up in a lead lined (got to protect from cosmic radiation) vault for 30 years, maybe spinning disks is the answer. But for most back up purposes its short term, to recover from a recent crash, and I would suggest SSDs are both more stable and faster.
Before SSD's were cheap I used spinning disks for backup, but MacOS would poll the drive every now and then, resulting in spinning it up (with the resulting noise) and the whole system would pause and wait with the spinning beach ball. Made things laggy, not to mention put wear and tear on the drive (like landing a plane the largest stress on a drive is start up and stopping) and thus defeating your claim of long term stability. The alternative would be to set the OS such that the drive never went to sleep, but this would drain power, and increase noise.
Not to mention, the smaller size of a SSD makes them easier to unplug, slip in a pocket and head home for off site storage. Or if you know, the building catches fire.
So yeah. SSD all the way for backups now that they have gotten cheaper. The exception might still be for very large video libraries (> 4 tb).