The Definition of Bad track
- 1.Physical Bad Track
- 2.Logical Bad Track
- 3.Initial Test of Bad Track
- 4.Overview of Misunderstanding
- 5.Data Recovery for Bad Tracks
A sector is damaged, if content can't be normally read out from or written into it. The magnetic track, that this bad sector lies in, is called bad track. Of course, this bad track appears because of software errors or hardware failure of hard disk itself. Therefore, bad track includes physical bad track and logical bad track. But, this doesn't mean that a hard disk with bad track can't be used. Actually, data on this hard disk can be recovered if users' disposal method is correct.
1.Physical Bad TrackPhysical bad track is caused by the failure of magnetic media on disc (may be because of scratch or rough production process). This makes hard disk can't read and write. Users can't repair the hard disk, so they have to abandon it. Physical bad track varies according to the area where it appears. If it appears in the middle place of disc, it can be bypassed by pinpointing the specific location of each disk in MBR partition table. So, the bad track isn't in any logical drive and is never be accessed. Some disk space is lost, but the device can be normally used. If sector0/0/1, namely track 0 is damaged, when startup reads MBR, 0/0/1 address reading calls issued by BIOS can't be completed. And start will be terminated.
2.Logical Bad TrackBad track may be caused by logical address mark error of the first sector (this is because of improper software operation or use). Such problems can be solved by using professional repair software, such as PC 3000 and training program of efficient source. This kind of bad track is called logical bad track or soft bad track.
The “Surface Test” feature of MiniTool Partition Wizard can be used to scan the disk and mark the bad sector. If there are bad sectors, please transfer all data on the target disk out firstly and then use a piece of specific software to shield these logical bad tracks. How to operate this “Surface Test” feature? Pease click to visit this post: Disk Surface Test.
3.Initial Test of Bad TrackIf hard disk encounters the following phenomena, users should notice whether there are bad tracks on it:
(1)When a file is read or a program is ran, hard disk is repeatedly read and has error prompting file corruption and other information; or it needs a long time to finish reading and sometimes there will even be a blue screen on computer.
(2)The sound of hard disk suddenly turns into strange sound from the original normal friction sound.
(3)System can't start normally excluding the reason of virus infection. The prompt message of “Sector not found” or “General error in reading drive C” appears.
(4)When hard disk is formatted, operations interrupt at a certain schedule. And finally computer prompts error suggesting that operations can't be finished.
(5)Scandisk will be automatically run to scan disk error each time when computer is started.
(6)When you perform FDISK on hard disk, the operations to a schedule will be repeatedly forward and backward.
(7)System can't be booted by hard disk when you start computer. You can go to drive letter after starting system with floppy disk, but the drive can't be entered. Even if you conduct system by using SYS command, the drive still can't be entered. This situation appears mostly because there is a problem with the boot sector of disks.
4.Overview of Misunderstanding(1)Logical bad track can be repaired while physical bad track can't. In fact, bad track is divided into bad sector recorded according to logical address and bad sector recorded according to physical address rather than being divided into logical bad sector and physical bad sector.
(2)There is no bad track on hard disk when it leaves factory. If users find bad track, this means that hard disk may become useless soon. In fact, every disk records a certain number of bad tracks before it leaves factory. And some disks even records up to tens of thousands of bad tracks.
(3)The hard disk can't be repaired, if it can't be found. You can use partitioning methods to solve the damage problem of track 0. The reality is that a considerable part of disks, which can't be found, can also be repaired. But, it's difficult to partition when track 0 is damaged.
5.Data Recovery for Bad TracksWhen we make sure that a hard disk has bad track, we still can't be sure that the bad track is caused by logical damage or physical damage. Because the requirement in the inside working environment of hard disk is very strict, damage will be caused even if a little dust enters inside of hard disk. You can't repair hard disk by opening it, but you may fix it with some software. However, most of current data recovery tools on market can only deal with logical bad track situation or doesn't give consideration to physical bad track situation at all. In the case of logical bad track, the recovery effect is still not ideal for some cases.
Therefore, once catastrophic data damage appears, even if you have previous backup, you shouldn't immediately restore the hard disk (if you perform writing operation, this may result in the coverage of useful data on hard disk, letting data be damaged again). You should turn to professional data recovery personnel to test in order to find out where the problem is. For the hard disk problem, further data recovery is a kind of powerful way to solve the catastrophic data failure on hard disk. During the process of recovering data, recovery measure only achieves dealing with the system problems or recovering data on storage device. It only performs reading operation rather than writing operation on hard disk. This can avoid secondary damage to data on hard disk.