Does a Hard Drive Remember Bad Sectors After Formatting?

does-a-hard-drive-remember-bad-sectors-after-formatting photo 1

If you start encountering bad sectors on your hard drive and decide to format it, will it “remember” those bad sectors afterward or not? Today’s SuperUser Q&A post helps answer a curious reader’s question about bad sectors and formatting.

Today’s Question & Answer session comes to us courtesy of SuperUser—a subdivision of Stack Exchange, a community-driven grouping of Q&A web sites.

Photo courtesy of Scott Schiller (Flickr).

The Question

SuperUser reader chris wants to know if a hard drive remembers bad sectors after formatting:

On an NTFS-formatted hard drive with some bad sectors, does the hard drive still remember those bad sectors after Windows diskpart clean is used to remove the NTFS volume? What if clean all is used?

Does a hard drive remember bad sectors after formatting?

The Answer

SuperUser contributors Ben N and harsh have the answer for us. First up, Ben N:

NTFS remembers bad clusters. A cluster is considered bad if any sector in it is not accessible. Since the bad cluster information is stored in a specific file ($BadClus), that information will be destroyed if the NTFS volume is removed. clean and clean all are essentially the same in that regard. clean all does a more thorough job of destroying the disk’s data while clean just wipes the partition table.

Further Reading: NTFS System (Metadata) Files

The hard drive is what remembers bad sectors. Exactly how it does that depends on the model, but most modern hard drives automatically detect and remap dead sectors so that the operating system does not even know there is a problem. In that case, nothing the operating system does can affect the disk’s internal bookkeeping.

Followed by the answer from harsh:

If the operating system is encountering bad sectors, then the hard drive’s internal bad block table is probably full (as Ben N pointed out) and it is time to retire the hard drive. Hard drives typically do not stop failing.

Have something to add to the explanation? Sound off in the comments. Want to read more answers from other tech-savvy Stack Exchange users? Check out the full discussion thread here.

More stories

How to Free Up Space Used By Your iPhone or iPad’s Mail App

Apple’s Mail app doesn’t provide a lot of control over how much storage it uses. it wants to download and store a lot of emails so they can be indexed and searchable with Spotlight. But the Mail app may sometimes use a large amount of space, which is particularly onerous on storage-limited 16GB

How to Create Animations with Your Philips Hue Lights

Sometimes, all you need out of your Philips Hue lights is for them to just turn on and off when you want them to, but if you’re hosting a party or just want to entertain your kids, animating your lights is a great way to kick things up a notch.

How to Clear Your Browsing History in Safari for iOS

Clearing your history from time to time shouldn’t be misconstrued as sneaky. It’s actually just a good practice to undertake. Over the course of time, you’re going to visit hundreds or even thousands of websites on your computer or smartphone. Not all these websites will necessarily be ones you’ll

How to Apply Local Group Policy Tweaks to Specific Users

For users of Windows Pro or Enterprise editions (and the Ultimate editions of Windows Vista and 7), the Local Group Policy Editor offers quick access to a number of powerful features you can use to control your PC. If you want to apply policy settings to specific users instead of the whole computer,

How to Customize Your Xbox One’s Privacy Settings

Microsoft is no stranger to controversy in the world of privacy, so it’s not too surprising that its flagship Xbox One console comes with such an extensive range of customizable privacy features. Users can configure dozens of settings, from how visible their gaming content is on Xbox Live down to