Sopel97

Note that any sane RAID software will limit the size used on each drive to the size of the smallest drive in the array.

As mentioned the 4TB Barracuda is an SMR drive. These are pretty useless for RAID as their write speeds are abysmal. In case a resilver is needed it'd take like 10 times longer than with CMR drives, completely defeating the point of RAID. See https://www.servethehome.com/wd-red-smr-vs-cmr-tested-avoid-red-smr/

At least ZFS allows increasing the size of the drives within a mirror pool. Not sure about other RAID setups but it's a pretty easy feature to support so I would expect virtually everything to have it.

You need at least like 5-6 drives for double parity to be economical. Aside from that you need backup.

You might be able to save the data, with minor chunks missing. The drive, not so much.

It'll just flag/correct if possible whatever inconsistencies you have in the filesystem, with its native tool.

Nothing wrong I guess, as long as you don't care about the data

and what good would chkdsk do on the image?

Use a Windows machine and chkdsk.

NEVER do that

For good measure you can do a surface scan too

yea, sure, kill it completely

Yes, it's one of the worst portable drives line to ever exist.

Also, see https://www.backblaze.com/blog/drive-failure-over-time-the-bathtub-curve-is-leaking/

I'd be surprised if you'd be legally allowed to handle such data with any of the programs suggested here. It'd be best if you reached out to whoever is responsible in your department.

this generally happens when you buy the trashiest externals on the market

any transcoding in this setup would be an indication of a configuration or plex error

I would do a single ZFS pool with the three drives.

that would be ideal

So if you have 6 SAS drives running 24/7 the turnover point from this investement would be at roughly 5 years. IMO not worth it at all.