Would an SSD be a good option as a backup drive?
There are two ways to interpret, approach, and answer this question:
- Are SSDs good for backups?
- Are backups a good use for SSDs?
The first question asks about reliability of SSDs for long-term storage. The fact is that SSDs just have not been around long enough for sufficient data to be accumulated and analyzed to provide accurate statistics on how long they last. Moreover, they have change quite a bit and very fast since they became popular, so what may be true for one drive, may not be true for an even moderately newer drive.
There is no single, universal answer to question one. It depends on the age, make, and model of the drive in question. One drive may be terrific and reliable while another is not. Your best bet would be to find some reviews for the drive you are considering purchasing and see what others who have used it have to say. If it has a lot of negative reviews, find another one. If it has mostly good reviews, take a quick look at the bad ones to see what specifically was the problem (they may only be about speed, or compatibility or something as opposed to failure).
The second question does have a single, universal, definitive answer: YES. SSDs are basically just large flash drives and as such their cells can only be written a limited (albeit large) number of times before they break down. This means that they are no good for things like temp-directories or page-files which have lots of writes, but backups by their nature are written very infrequently (basically only one write per file per backup interval period).
Because backup drives have very few writes, it makes backups the perfect (even ideal) use for SSDs.
Is S.M.A.R.T. available over USB (3 or 2). [I do have eSata, so this isn't all that important]
I’ve seen this question a lot over the past few years. As Sergey pointed out, it should be possible with the right combination of hardware and software. I have seen some programs purport to be able to read SMART data from USB devices and even RAID drives, but I have not personally seen one that works yet.
Can you TRIM over USB (3 or 2)? If not, is there a way to optimize the drive after the fact?
It doesn’t seem to be , but would you even need to for a backup drive?