Disk has a few bad sectors?

[boxerfangg]

Hello everyone, I have two hard drives, one with Ubuntu and the other with Windows Vista.

Today I tried to boot up Vista and it took forever and when I got logged in everything was completely unresponsive. I noticed the HDD light blinking every second and decided to check the disk in Ubuntu Disk Utility.

SMART status says the disk has a few bad sectors, about 1,119 bad sectors.
Also SMART data is giving me a warning on Reallocated Sector Count, value field says:
Normalized: 100
Worst: 100
Threshold: 36
Value: 1119 sectors

Is this the problem for the very long boot time and unresponsiveness?
What should I do? I have important data on the disk, including the OS.

 

[corkyg]

Back up the important stuff ASAP. And, yes, . . . bad sectors can slow things down if they are in the boot sector.

 

[boxerfangg]

Could I just create an image of the disk?

 

[razel]

I would waste no time and backup those most precious data bits manually 1st. The ones that will make you cry if you do not have a copy elsewhere. Then I'd worry about imaging.

However, if I were you after the backup, I'd run the manufacturer's diagnonsis utility. You'll need to do the basic tests... usually a SMART check, quick then long. It's the long test you're most interested in. It will read the entire surface area and when encountering a bad sector, it usually will try to recover data from the bad sectors and replace it with good ones.

If it's really bad, it will often give you options for RMA, otherwise you can proceed. Back in Windows I'd go into the commnd prompt and do sfc /scannow which will verify your core windows files. If that checks out, I'd do the image backup and move on with life.

 

[FishAk]

^^ Excellent advice. Save- fix- image.

 

[pcgeek11]

^^ Excellent advice. Save- fix- image.

Here is some better advice:

Get your data off the drive.

Replace the drive with a new one. It is not worth the effort to do anything else, the drive is failing and it will only get worse. Even one bad sector is too many. Drives are cheap.

 

[FishAk]

Here is some better advice:

No, that's not better advice- in fact it is terrible advice.

Like razel said...

First priority = save the data

Second priority = Fix the drive- recover what's possible using the OEM tool

Third priority = Image the drive

That is the best advice. Once the image has been made, what happens with the drive is irrelevant. The previous posters have made it quite clear that the drive is failing. Only a fool would think they should continue using a failing drive, and there are no fools on AT.

If the OP follows razel's advice, all that can be salvaged from the disk will be, and then it is simply a brick. If the drive doesn't make it to the image stage, well, hopefully he got what he could from the first step. But if it makes it to the end, now the OP has an image that can be put on the new drive- one that is current.

Replace the drive with a new one. It is not worth the effort to do anything else

If the OP takes your advice, does nothing with the failing drive, and only installs a replacement, the OP must rely only on his backups. Any info only on the failing drive will be lost. Additionally, the OP will have to reinstall from scratch if an image of the OS wasn't produced previously.

 

[razel]

Ouch pcgeek... didn't ya read everyone's advice? It's essentially the same thing you claim is 'better.'

 

[taltamir]

Here is some better advice:

Get your data off the drive.

Replace the drive with a new one. It is not worth the effort to do anything else, the drive is failing and it will only get worse. Even one bad sector is too many. Drives are cheap.

this is indeed superior advice.

1. Back up most important files, manually.
2. Back up the rest of the files you want to keep, manually.
3. Throw current drive in the trash (or get it replaced under warranty) and get a new one.

DO NOT UNDER ANY CIRCUMSTANCES IMAGE THE DRIVE!
1. Imaging attempt greatly increases the chance of the drive failing without you getting your important data back.
2. If you had already backed up your important data, imaging the drive will give you an OS install with CORRUPT OS FILES. This will cause bizzare and unique and annoying things to happen. You want to do a fresh install from the windows / linux DVDs not a clone with corrupt files. And you want it on a new drive.

 

[FishAk]

imaging the drive will give you an OS install with CORRUPT OS FILES.

You are seldom wrong, taltamir. But in this instance you missed the essential second step of razel's advice. If the sectors can be reallocated, and sfc /scannow verifies the files are OK, the image should be valid.

 

[Mark R]

Indeed, if the sectors have been lost/corrupted when going bad, the imaging procedure should fail.

It is almost inconceivably rare for a hard drive to return corrupted data from a bad sector - instead, it will give an error. Most imaging software will panic and stop the imaging process (or will give you loads of warnings telling you that the image might be corrupt).

 

[taltamir]

you raise a legitimate point.
However, since we don't know what is causing such a high bad sector count, could it not be a problem with the drive that might also results in silent data corruption?
And how well does windows update handle bad sectors during install?
And what if he had unrecoverable bad sectors on OS files which have been reallocated some time in the past, say, last week? Even if not recoverable the sector would have been reallocated and the file left corrupted. Would an imagining tool catch that (I don't believe so)?

 

[jiffylube1024]

1000+ bad sectors is definitely cause for concern. When you said "a few" bad sectors I was thinking 5-10.

Bad sectors are a sign that the surface of the disk is becoming unreadable. I've seen quite a few hard drives develop 1-8 bad sectors within a year or two of operation. This is a bad sign, but it's primarily because a few bad sectors can lead to hundreds down the line. I've had drives with 1 or 2 or 3 bad sectors stay pegged at that number over 2-3 years of operation, with no further problems.

However, if you've already got 100 bad sectors, let alone 1000, you've got a big and probably growing problem on your hands. It means your data is at risk of disappearing.

I would follow most people's advice -- plug a second hard drive into your computer, and manually back up your high-priority files first (important documents), then your less high priority files (photo albums, other documents, etc). Keep going down the line and copy your lower priority stuff (music, movies, etc).

Now, if you want to, you can image your drive, but only once you've gotten what you want off the drive manually. I've seen people try to image a whole failing hard drive and inevitably the image fails midway through because sectors can't be read, and sometimes the failing drive then becomes unreadable.

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Finally, I'd like to add one more thing. After you've gotten what you need off the drive, it's still a good idea to format it and either write the drive with junk files or use a "file shredder" program to erase your files securely (by writing the drive with 0's or randomly generated junk).

While your drive may become unstable to read, it could still be read by someone else down the line if you don't personally destroy the disk. Most people have files saved on their computer that they don't want other people to access. It's a good idea to clean your disk by writing it with junk or a file shredder program so someone in the future doesn't have access to all of your documents/files/etc.

this is indeed superior advice.

1. Back up most important files, manually.
2. Back up the rest of the files you want to keep, manually.
3. Throw current drive in the trash (or get it replaced under warranty) and get a new one.

DO NOT UNDER ANY CIRCUMSTANCES IMAGE THE DRIVE!
1. Imaging attempt greatly increases the chance of the drive failing without you getting your important data back.
2. If you had already backed up your important data, imaging the drive will give you an OS install with CORRUPT OS FILES. This will cause bizzare and unique and annoying things to happen. You want to do a fresh install from the windows / linux DVDs not a clone with corrupt files. And you want it on a new drive.

 

[pcgeek11]

Ouch pcgeek... didn't ya read everyone's advice? It's essentially the same thing you claim is 'better.'

No it isn't the same. Why spend hours trying to polish a turd. With that many bad sectors it isn't worth the time to try and image it. Get the data, get a new drive.

 

[FishAk]

This is why it's so important to keep an image set on multiple disks, and know how to use them. It only costs a little time and some disk space. The software is free, powerful, and very easy to use.

Most people don't know what to do when they hit the power button, only to find themselves staring at a black screen with a line of test, or a flashing white line. The solution is simple for the prepared, but a nightmare for everyone else.

For someone who has only a few programs, and uses the default settings, a reinstall/update shouldn't take more than a few hours. But for someone with a lot of customization, it can take several days- and they might not even find all the tweaks and apps that they liked.

If the OP is in the second group, but doesn't have a good image with all the customizations, it's possible to save a considerable amount of time by trying to salvage an image from the toasted disk. If the salvage operation doesn't work, a couple hours will be lost at worst. If, on the other hand, it does work, literally days can be saved over the alternative full install.

For anyone who doesn't just use the default OS, and a handful of programs, given the risk/benefit, it would be silly to just toss the disk without trying to get a valid image of the OS.

Jiffylube brings up an excellent point. An attempt should be made to destroy any info on the disk before disposing of it. Better yet, is to use full disk encryption all the time. TrueCrypt is free and very easy to use. With a modern processor, it's not possible to perceive a performance hit. Even data on relocated sectors can't be recovered without the password, so there is no reason to try to further destroy any data.