ST2000DM001 head 2 does not read after few sectors

[Imnew]

Hello, I have HDD ST2000DM001. It has 5 heads and is identified perfectly. 7X in terminal shows perfect heads. When imaging, can image heads 0,1,3,and 4 perfectly. But head 2 does not read after 47,0000000 sectors. Is it a head problem or some other issue.

[DataMedics]

Probably is a head problem. If it were translator related it'd affect all heads, not just one. Could also be just media damage, have you tried jumping ahead a few million sectors and see if you can get past the bad area? Or even try imaging backward with the head.

Also have you tried clearing a bit of the map and reading it again with head 2 to see if it's just failed now? It's not uncommon for a head to die during imaging. Could just be that's where it was when it died.

[lcoughey]

It is very common for this drive to have a bad head, even though it looks perfect at the start. Recently had a drive that mirrored all heads at about 107MB/second for about 10% of the drive, then head 2 started to show errors until it basically wasn't reading at all. Mirrored the good heads, changed the heads and mirrored the remaining surface with very few errors.

[lcoughey]

Just got another one in. This time with head map 0,1,2,3 and head 2 being dead within a couple percent of the start of the drive.

[DataMedics]

I too have noticed a lot of them where head 2 was the culprit. Must be something about their manufacturing process, or design of their drives.

[Imnew]

I have tried backward imaging also. Same. All heads are working perfect except head 2. No imaging after 470000000 sectors. If it would have been head problem, it should not copy initial sectors also and if it is a translator issue, then imaging from all heads should show problem. Thats why I am puzzled. Why only one head is not copying after certain sectors ????

[lcoughey]

Just did another DM drive where head 2 is the culprit. At first, all heads would read and within the first few percent, head 2 would not read at all. Mirrored heads 0,1,3 100%, changed heads and am now mirroring head 2 at about 104MB/second, at 25% with absolutely no read errors, thus far.

[DataMedics]

Source of the post I have tried backward imaging also. Same. All heads are working perfect except head 2. No imaging after 470000000 sectors. If it would have been head problem, it should not copy initial sectors also and if it is a translator issue, then imaging from all heads should show problem. Thats why I am puzzled. Why only one head is not copying after certain sectors ????

Try creating a new task and see if head 2 is still reading in the lower sectors. My bet is the head died during imaging, and now doesn't read at all. Happens all the time.

[Imnew]

No the head did not die completely. Tried creating a new task. Same situation. Can someone from ACE guide on this.

[Nick_TS]

Hello,

Looks like it is combination of head issue and translator problem.
There are two ways to solve this problem:
1. Try to repair translator with bad heads (it requires deep knowledge in translator recovery, manual rebuilding NRGL and a lot of time)
2. Replace heads and try to recover translator by utility tools.

[Imnew]

Hi, How to do translator recovery with only bad head ??

[DataMedics]

I think what Dmitriy is trying to say, is that it's way more complex and time consuming than what is really practical in the situation. Need to replace the heads bro.

[gterry]

Some info that I found today that may relate to this old thread. I have a similar issue with a ST3000DM001 except it was head 1. All other heads read fine so I turned off head 1 and imaged the drive without error. Then I tried imaging in reverse for head 1 and still had issue, I also noticed a different sound with the heads reading with 1 activated so I assumed it was bad or there was surface damage. I removed the heads and head 1 didn't show any scarring on its surface. I have a lot of these drives so parts are not an issue. I replaced heads with the HDDSurgury Tool and tried a random read spot for head 1. It would read with errors still and seemed like there was random surface damage because of the pattern of errors and ok reads. The heads were also making the same noise as before. So I disabled read-look ahead and the noise went away and it started reading fine without errors. Strange that one head was affected by that and that it persisted in the original heads and the new ones. So long story short, give that a try next time and see if it fixes the issue.

[lcoughey]

Source of the post Some info that I found today that may relate to this old thread. I have a similar issue with a ST3000DM001 except it was head 1. All other heads read fine so I turned off head 1 and imaged the drive without error. Then I tried imaging in reverse for head 1 and still had issue, I also noticed a different sound with the heads reading with 1 activated so I assumed it was bad or there was surface damage. I removed the heads and head 1 didn't show any scarring on its surface. I have a lot of these drives so parts are not an issue. I replaced heads with the HDDSurgury Tool and tried a random read spot for head 1. It would read with errors still and seemed like there was random surface damage because of the pattern of errors and ok reads. The heads were also making the same noise as before. So I disabled read-look ahead and the noise went away and it started reading fine without errors. Strange that one head was affected by that and that it persisted in the original heads and the new ones. So long story short, give that a try next time and see if it fixes the issue.

I have one here now, with head 1 that reads only for less than 1% before not reading at all. Disabling read-look-ahead, both in DE and via module 93 did not net any different result...head 1 still didn't read. In every case like this, I've almost always had good luck with changing the heads and reading head 1 at full speed.