nicad wrote:
correct. I am seeing the 0 size capacity when right clicking the drive in my computer.
Understood, so my related comments above re: filesystem corruption apply.
nicad wrote:
the files that I have managed to copy before receiving I/O errors (in my virtual bootCD environment) are fine.
You were lucky, as I explained re: corrupted filesystems.
nicad wrote:
I will get the SMART data and reply with it here. I did run the SMART test via the seagate tools and it came back fine. the Short DST test did fail, however
Yikes! So this confirms a hardware fault with the disk, as I suspected.

It's
likely that unreadable sectors (pending or already reallocated) will be seen in the SMART data. Please confirm that Seatools does show what is called "raw" values for each SMART attribute. If it does not, then it is not suitable for supplying the data I requested and HDDScan should be used (from hddscan.com).
nicad wrote:
what could be causing these I/O interruptions?
As I explained in my previous comment, I suspect unreadable sectors are the cause (common with 7200.11 drives, in my experience) - the SMART data will show whether this is true or not. The failed Short DST certainly confirms some kind of fault with the drive.
You didn't answer my question about whether or not you needed to power-cycle the drive / system, once the "anomalies" & I/O errors started, before any more files were readable during your testing. Did you miss that question? Do you understand what I mean?
If your data on the drive is of limited value, and if you are happy to take DIY risks and not to involve a DR company, then the typical approach for a drive which could deteriorate at any point (like this one), would be to try to clone
the whole drive ASAP to a drive of the same (or larger) capacity (e.g. using Linux ddrescue or other programs specifically designed for cloning). However if the data does have value, then before things deteriorate, a DR company with dedicated hardware cloning equipment has a better chance to get a more complete image of a faulty drive, than a software-only DIY approach.