Oddly enough, this question happens to have a rather straightforward answer. Let’s get to that with an example. Let’s say that you are planning to fix the bad sectored drive with CHKDSK. If you care about the data contained on that hard drive, then this is not going to work, at the least in the long run.
Let me explain why that is.
Although it is a common belief that CHKDSK will not work, it could actually be of some help but only temporarily. Sooner or later, the HDD with the bad sectors masked by CHKDSK will fail. This will result in a complete loss of data and your only course of action will be professional assistance.
Here’s what happens when you attempt to use CHKDSK in this manner:
This is how the CHKDSK function operates on drives that contain bad sectors. It will allocate the sectors but rather than repairing them or removing them completely, CHKDSK sort of performs a ‘cheat’ on them. What it does is it will ‘mask’ remove them from the accessible point of partition. It may sound like a good idea making the bad sectors difficult to access which would, in theory, solve the problem, right?
Well, that’s not really solving the problem whatsoever. In fact, the CHKDSK function basically ‘hides’ the problem for discovery at a later time.
Maybe this will make it a little easier to understand for you.
It’s sort of similar to hiding garbage under your bed to make the room look clean, and then wondering why the room starts to smell bad at a later time.
It’s the same basic concept here.
The bad sectors are hidden from sight if you will. So the disk can continue to function although it still has bad sectors within it although they appear to be gone. Those bad sectors will quietly exist on your disk and may lead to further complications.
I’ll give you a couple of examples of what can happen with disks that you run CHKDSK on.
Bad Sectors are a sign of a mechanical failure.
Bad sectors are still considered by some to be the result of logical issues. However, that is not true. Bad sectors are not a logical type of failure but are in fact mechanical in nature. This makes them mechanical failures and a good starting point of the possibility of the Gimbals Head Stack assembly failing completely in short order. You read that correctly, this type of mechanical failure can quite easily be the tip of the iceberg. It is without a doubt a sign of worse things to come and often that is a major failure such as the HSA.
By running CHKDSK you are essentially hiding the fact that a bigger issue is looming in the background that could jeopardize your data. This is why you should avoid using CHKDSK in this situation.
However, the drives that contain bad sectors are often recoverable with software. Think about that for a moment. If you can remedy the issue using recovery software what does that typically mean? If you said that it would point to a logical failure, you would be right. But I’ve already explained that bad sectors are in fact not logical failures. They are mechanical. This is where the confusion comes from making bad sectors appear to be a logical failure.
It is kind of confusing until you understand the difference between logical and mechanical failures.
So, how exactly can you combat the issue of bad sectors?
The smartest thing you can do is to clone the drive or copy the data on that disk that is of major importance to you. There is one important thing to keep in mind. When using the software it can skip over bad sectors. When this happens, it will take a long time in order to completely copy the disk. This means that you really must be patient when conducting this process.
Another situation is hard drives with several bad sectors on them. These are drives that won’t let you copy anything from them or they will only permit you to copy small portions of the drive. When you have a drive in this condition it tells you that the problem has been in place for some time. What I mean is that the drive would have initially had a few bad sectors. Over time, that situation progressed to the point where a severe mechanical issue has developed with numerous bad sectors.
The most likely solution to that scenario is a complete swap of the Head Stack Assembly.
Should you be backing up on a drive in that condition (filled with bad sectors)?
It is probably not such a good idea after all.