Shield Bad Tracks by Zone/Head in Seagate HDDs

Download link of video tutorial: http://us.mrtlab.com/video/sgthidbadsebyhed.rar
Released: March 5th, 2015

     When bad tracks appear regularly in hard drive, there is very likely to be radical scratch on platter or problem of head. The features "Cut head" and "Cut zone" in Seagate are still under development. At the moment, for radial scratch on platter, we can shield bad tracks by zone to shield the scratched zone. For hard drive with head problem, we can shield bad tracks by shielding head so as to disable the area controlled by damaged head. In this way, other good heads can be used. The operation process of these two features is similar. So here we illustrate them in the same tutorial.
     First, let’s see how to shield bad tracks by zone. Here is a disk for demonstration.

Step 1:
Let’s scan to see the disk status. This is a Seagate 7200.12 disk. Since there is a damaged head, the range of bad tracks is wide, so we need to check "skip when there are bad tracks" to save time. Record the location of bad tracks – LBA 26624. The first group of bad tracks should be located in the same zone. Now the second group of bad tracks is encountered. Let’s try to shield the zone where the bad tracks locate. First, we should determine which zone it is. Select several LBAs to test. LBA: 26624,331008,410880. Then we check the LBA information with address translator.
26624: head 0, zone 0
331 008: head 0, zone 0
410,880: head 1, zone 10 (hex)

Since we have found the head and zone where the bad tracks locate, let’s shield it.

Step 2: Shield zone of specified head.
In order to avoid being affected by G-List, let's clear G-List first. Open the menu Tools -> Disk repair tool -> Shield bad tracks by zone
This list will show all the sub-zones of each head. Please note that the zones listed are sub-zones, not major zones.
Let's look at major zones first. Input command “x” in 2 Level. The selected part is major zones, i.e. zone 00 - zone 10
Actually each major zone is divided into many sub-zones. Head switching is done according to sub-zones, not major zones. For example, ZONE 00, with starting track and ending track being 000000 and 0003D3, can be divided into multiple sub-zones. Let’s look at the starting track and ending track of each sub-zone. Shield zone -> Advanced tools, there lists head number and major zones of each head. Decimal 0 -16 correspond with hex Zone 00 - Zone 10. Check the major zone 00 of head 0, the program will automatically check corresponding sub-zones. We can see there are many sub-zones included in Zone 0.
We can shield each sub-zone individually, or shield the entire major zone.
Now we check the major zone to be shielded.
Select head 0, major zone 0, and head 1, major zone 10 (=decimal 16), the program select the corresponding sub-zones automatically.
Write to disk in ATA mode.

Step 3: If there are many zones to be shielded, we need to reduce the capacity first.
This step is optional. While sometimes if you don’t reduce the capacity before recalculating translator, it can fail or succeed with no actual effectiveness in recalculating translator. If many zones are shielded, the capacity of hard drive will surely be smaller. So we need to modify the capacity of hard drive first. Note: the reduced capacity should equal the total sector length of shielded zones. Most important of all, we should modify the capacity in RAP. The capacity in CAP and modules has little effect on shielding zone and head. Menu of modifying capacity in RAP: Tools -> SA Tools -> Modify RAP. Here we also modify the capacity in CAP.

Step 4: Recalculate translator
Clear G-List with command “i4” to avoid affected by data of G-List. Then recalculate translator with command “m0,6,3 ,,,,, 22”.
This step usually takes a long time. Here we pause videotaping to save time.
We can see that recalculating translator failed. This fault can usually be encountered by users. There are several possible causes. The first possible cause is capacity not modified. The second is that there are repeated entries (conflicting entries) in P-List. For this, we will illustrate the solution in the following part “shield bad tracks by head”. Here we should make sure that Step 3 - Modify HDD capacity is completed. We can see that after modifying capacity in RAP, recalculating translator succeeded.

Step 5: Erase sectors
There are several optional schemes for erasing sectors, the first is to format the disk with command “m0,8,3 ,,,,, 22”, the second is scan in “Write” mode, the third way is to use the erasing function of security subsystem. Here we erase the sectors by scanning in “Write” mode. To save time, we will only erase part of sectors. When users finish erasing the whole disk, they can do normal scan. Users can se

 
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