e the zones with bad tracks have been shielded.
Above is the operation process of shielding bad tracks by zone.
Then let’s demonstrate how to shield bad tracks by head. Here we user a Seagate 7200.11 hard drive.
The operation process of shielding bad tracks by head:
Step 1: Scan the hard drive to determine which head needs to be shielded.
We see this hard drive showing typical symptom of weak head. Selected a LBA to test which head is weak.
We can see from the tested LBA that head 0 is weak. It needs to be shielded.
Step 2: Shield specified head
Clear G-List. Then go to ATA mode, open the menu Tools -> Disk repair tool -> Shield bad tracks by head
Select the head to be shielded, click “OK”. Then area controlled by the head is added to defect list.
Step 3: Recalculate translator
Clear G-List with command “i4”, and input the command “m0,6,3 ,,,,, 22”.
It takes a long time to be completed.
This step is the most prone to problems. Now let’s consider that if there is error in this step, what should we do? We can see there is LED error when recalculating translator. In this case, recalculating translator failed. As a result, shielding bad tracks by head will not succeed.
We can try to solve the problem with the following three ways:
1. Update firmware
Sometimes we need to update firmware to shield head successfully. Download firmware package provided by MRT, and write the compatible firmware of newest version to disk.
This hard drive is 7200.11. We should use SD1A. If it is 7200.12, we should use CC49.
After updating firmware, repeat Step 2 and Step 3.
If it still fails, try the second method.
2. Delete the entries in P-List which belong to the shielded head.
Recalculating translator failed may be caused by repeated entries (conflicting entries) in P-List. We need to delete them. Take shielding head 0 as an example, we should delete the entries in P-List which belong to head 0. Then repeat Step 2 and Step 3.
Let's restore translator first and then delete entries of P-List. Write edited P-List to disk.
Repeat step 2 and step 3.
Generally, recalculating translator will succeed (especially for 7200.12 disks).
But failure can still occur in some hard drives. Then try the third way.
3. Reduce capacity in RAP.
Minus the capacity of area which belongs to shielded head with RAP capacity. As a head is shielded, the capacity will surely be decreased.
Modify the capacity with the menu "Edit RAP ". Remember to power off the disk and then power on so that the modification can take effect.
Repeat step 2 and step3.
With the three methods above, we can shield head successfully.
Recalculating translator can take a lot of time.
Generally speaking, for 7200.11 hard drives, it usually takes at least 5 hours to recalculate translator with command “m,0,6,3,,,,,22”. While for 7200.12 hard drives, the speed is much faster as the algorithm of recalculating translator is optimized in 7200.11 hard drives. Now we pause videotaping and continue when recalculating translator is completed.
Recalculating translator completed. Let’s go to the next step.
Step 4: Erase sectors.
There are several optional schemes. The first is to format the disk with command “m0,8,3 ,,,,, 22”. The second is to scan in “Write” mode. The third is to use the erasing function of security subsystem. Here we scan in “Write” mode to erase the sectors. To save time, we will only erase part of the sectors. Users should do normal scan after completing erasing the whole disk. Then we can see the area controlled by damaged head has been shielded.
Above is the operation process of shielding bad tracks by head.
Next, we connect the 7200.12 disk again to demonstrate the whole process of shielding bad tracks by head.
We can see that the process succeeded even with there being repeated entries in P-List. If it fails, we can delete the repeated entries in P-List and try again.
Above are the operation processes of shielding bad tracks by head and shielding bad tracks by zone. Thanks for watching.
This tutorial is released by MRT Lab http://www.mrtlab.com
For purchasing MRT products: https://us.mrtlab.com/prodindex.htm
Download link of video tutorial: https://us.mrtlab.com/video/sgthidbadsebyhed.rar
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