I have an odd issue on a 3TB Seagate. The drive reads flawlessly through the first 10%. No problems, no slowing down, nothing. Just blasts right through. It then hits intermittent areas where it almost comes to a complete stop. In DDI, it will just hang in BSY state after it skips a few sectors, and won't even restart or recalibrate itself properly. Just stays BSY and then errors out as unresponsive.

I can push it along by changing some of the imaging parameters, but it images very slowly, and at this pace would probably take a year or two to complete. It will then hit areas where it reads very fast again. Only to slow down a few hundred thousand or maybe a couple million sectors later.

There is no one head that reads better than the others. A head that may not be able to read one section of the drive, can read other sections with no issues, and that is how it is across all the heads.

It almost seems like the platter itself is degraded. Has anyone else seen anything like this?

It doesn't make sense to change heads, because I don't believe that's the problem at all. If the heads were bad, they would be bad across the entire drive.

The drive has been in an enclosure, on a shelf. It was never dropped, or mishandled in any way.

I had a 1tb 7200.12 the other week that would clone fine and fast up to about 71% and then slow down to a crawl (1% in a week) in large patches. New heads fitted and the rest was cloned fine and fast in a few hours.

_________________
PC Image Data Recovery
http://www.pcimage.co.uk

New!! HDD-PCB.COM for all your PCB and donor HDD requirements!

This thing is about to drive me crazy. I guess I could be wrong, but I don't believe it to be an issue with the heads. It seems like something firmware related almost.

Here's the pattern I've discovered while imaging. I have a head map generated. Most of you know that Seagate drives typically image sequentially, up and down the head stack. 0,1,2,3,4,5 and then 5,4,3,2,1,0

Here's what this drive does...

0 - fine

1 - fine

2 - fine

3 - fine

4 - becomes busy and freezes up just before switching to head 5. So I hit the space bar to skip and it moves on to head 5

5 - fine

5 - fine

4 - fine

3 - fine

2 - becomes busy and freezes up just before switching to head 1. Hit the space bar to skip and it moves to head 1.

1 - fine

0 - fine


So moving up the heads as it images, the drive freezes towards the end of head 4. Moving down the heads, the drive freezes towards the end of head 2.

Heads 2 and 4 work perfectly at opposite intervals. If I don't hit the space bar in time to skip...literally less than a second after it freezes up, then the drive stays in a BSY state. Even if it repowers it stays BSY. If I physically hit the F11 key though, and then repower the drive manually, I can pick back up from a different area of the drive and it continues to repeat the pattern above.

Logically I would say, ok, let's just deactivate those two heads. However, if I do that, I have the same issue on a different pair of heads. Might be heads 1 and 3 then.

This is one of the craziest things I've ever seen.

Sounds like a firmare issue as result to degradation. No bad sectors causing reallocation?

_________________
Hard Disk Drive (HDD), Solid State Drive (SSD, SATA, NVMe, etc), USB Flash Drive and RAID Data Recovery Specialist in Massachusetts

No, but I think I have it squared away. I've tweaked the DDI settings enough to get it going on its own without having to babysit it.