I have a 3TB hard drive, which is just over a year old, in an external enclosure.
I connect it to my Windows 7 desktop via eSATA.
The other day it disappeared from Windows, I had to power down the enclosure for a few minutes and restart Windows to get it working again. I didn't think much of it as this has happened several times before.
Yesterday, I was copying some larger files (about 5 files around 200MB each) onto it and on the last file I got an error, and found that the hard drive had disappeared from Windows again.
Again I powered down the enclosure for a few minutes and restarted Windows. This time the drive didn't show up.
I left it powered down for a while and restarted, finally the drive showed up.
However, I could not browse any files, it just hung and after a while I got an error "Unexpected I/O error has occurred".
I powered down the drive and restarted again, this time the Windows showed a message indicating that the drive needed to be formatted.
At this point, I hoped it was a problem with the enclosure's interface card.
I thought that the power problems may have corrupted the file system.
As well, the hard drive was not making any noises indicate hardware failure.
I went out and bought a new enclosure then connected it to my desktop.
Again Windows showed a message indicating that the drive needed to be formatted.
I ran chkdsk with the /R option. It fixed a bunch of indexing errors.
I quit the process during stage 4 (verifying file data) as it was taking fairly long.
The drive showed up in Windows and I was able to browse through my files.
I opened some as spot checks.
I left the drive alone for a while then went into a folder I'd already accessed since running chkdsk but this time encountered the I/O error again.
This is leading me to believe something is wrong with the hard drive.
Before I go out and buy another hard drive, I wanted to ask the following questions:
Is it possible that a problem with a file could cause the I/O error?
If so, would stage 4 of chkdsk fix this?
If the hard drive is the problem, what is a good utility to copy as much data off the drive as possible? I would like something that indicates files that could not be copied.
I am running chkdsk now, again at stage 4, I think it will take about 50-60 hours to complete at this rate.