Computer Help forum

General discussion

Bad/Unusable areas on a HDD. Common? Do they enlarge?

by jas1 / December 17, 2004 3:38 AM PST

Can I determine if my hard disk has areas marked off by the formatting process as being damaged and unusable?
- Can I determine the size of any such damaged areas?
- Is it common or rare for HDD?s to have these damaged areas?
- Finally, how likely is it that a damaged area will grow larger over time causing me problems in the future?

I have a Toshiba 40GB HDD (model MK4019GAX) in my 1-year-old Dell 8200 Inspiron notebook. But when I check the HDD under ?my computer?, the total size is stated to be 37.2 GB. So is it likely my HDD has a
damaged area of about 2.8 GB in size, or this it more likely that this Toshiba HDD is only 37.2GB but Toshiba rounds up the number to 40GB for sales purposes?____.

BACKGROUND:
Recently, access to the hard drive would slow down a hundredfold, making this notebook unusable. I ran Dell's HDD diagnostics and it found no hardware problems. I "repaired" the operating system (WIN XP
home) and the HDD began working fine for a day and then became 100 times slower again. I also ran Norton Disk Doctor and scandisk, both of which detected no problems.

A clean install, this time to WinXP Pro, apparently solved the problem. But when doing this clean install I monitored the disk reformatting as it advanced from 1% complete to 100% complete. It took about 1 minute to advance an additional 1% towards completion. But from 24% complete to 28% complete, this reformatting process took 30 minutes, slowing
down by a factor of 7. I suspect that this might be because the WinXP Pro reformatting process (for a clean install) encountered a bad area on my hard disk, and it took 7 times longer to work its way thru that portion of the HDD. But I can't find anyone to confirm my suspicion on this. What else might have been responsible for this slowdown? I did a complete NTFS reformat, not the ?quick? version. It took 130 minutes to complete.

WHAT TO DO NEXT?
I?m concerned about now spending 10-15 hours loading all my software applications on this notebook. I've been told that bad areas on hard disks often grow in size over time. Is this true?____ Does it occur
rarely or frequently?____ If true and not rare, then perhaps I?m better replacing my HDD now and not taking a chance of a damaged area (if I have one) growing in size and causing my notebook to become
inoperable again in the near future.

Thanks.

Discussion is locked
You are posting a reply to: Bad/Unusable areas on a HDD. Common? Do they enlarge?
The posting of advertisements, profanity, or personal attacks is prohibited. Please refer to our CNET Forums policies for details. All submitted content is subject to our Terms of Use.
Track this discussion and email me when there are updates

If you're asking for technical help, please be sure to include all your system info, including operating system, model number, and any other specifics related to the problem. Also please exercise your best judgment when posting in the forums--revealing personal information such as your e-mail address, telephone number, and address is not recommended.

You are reporting the following post: Bad/Unusable areas on a HDD. Common? Do they enlarge?
This post has been flagged and will be reviewed by our staff. Thank you for helping us maintain CNET's great community.
Sorry, there was a problem flagging this post. Please try again now or at a later time.
If you believe this post is offensive or violates the CNET Forums' Usage policies, you can report it below (this will not automatically remove the post). Once reported, our moderators will be notified and the post will be reviewed.
Collapse -
You might try...
by Edward ODaniel / December 17, 2004 4:12 AM PST

running the manufacturer's utilities to check on bad sectors but doubt seriously if that is where your problem lies (matter of fact I notice that you mention that Dell's tool didn't find any).

All drives may have bad sectors but have additionsl sectors to make up for them.

The confusion between binary and decimal math is apparently bothering you regarding drive size. Many hard drive manufacturers use the ISO definition of a "gigabyte," which is "one billion bytes," or "1,000 megabytes." But most people familiar with the binary nature of computers consider a gigabyte to be 1024 megabytes (and that includes an operating system's reporting tools). Thus, a binary gigabyte is somewhat larger than a decimal gigabyte, and that's where the bad blood comes from: Some consumers thought they were getting binary gigs, but actually got decimal gigs. On a large hard drive, the differential adds up.

Progress bars and numbers do not always tell the whole tale of what is happening--don't be reliant on them.

Since you have XP why don't you use the Task Manager to monitor your computer to determine the actual cause of your slow downs. You could really nail it down if you take advantage of other system tools like PERFMON.
http://www.microsoft.com/resources/documentation/windows/xp/all/proddocs/en-us/nt_command_perfmon.mspx

http://labmice.techtarget.com/windowsxp/Performance/default.htm

Collapse -
The Microsoft tool ...
by Kees Bakker / December 17, 2004 4:44 AM PST
In reply to: You might try...

to scan a hard disk is scandisk (full check, including surface check). If that detects not errors, I would trust the hard disk. It's a little bit hidden in Windows XP, but it still exists: see http://www2.sunysuffolk.edu/mandias/tips/scandisk_xp.html

Edward is fully right about the math and probable other causes for your troubles. But it feels good to know for sure that your harddisk doesn't have bad sectors. My advice for such a disk: replace immediately.

Kees

Collapse -
Perfmon and sysmon...
by Edward ODaniel / December 19, 2004 2:31 AM PST
In reply to: The Microsoft tool ...

are the tools to check on performance issues which he seems to be blaming on hard drive.

CHKDSK will not inform the user where the performance problems actually originate nor provide clues to eliminate the hangups described.

Collapse -
Flaws exist, but
by holtnr / December 17, 2004 9:09 AM PST

Manufacturers build in safeguards in the formatting process to work around the flaws. Manufacturing info about bad spots is stored in a disk cylinder that is inaccessable to anybody but the disk itself. In a low level format they may use complex repositioning algorhythms to avoid that spot, or they may just re-vector that bad block to the extra sector that is routinely written on most disks (one per track). In addition format specs frequently call for an extra cylinder or 2 just in case the ones in any particular cylinder are all used up. In addition they go to great lengths to hide this from the user. As long as they still have replacement blocks left to use, and as long as their failure predictions work, they will transparently move the data to a new location BEFORE it becomes unreadable, and the user will be none the wiser. Excessive re-vectoring can cause signifigant disk speed degradation, but MS's SCANDISK will pass the volume as perfect. I watched the scan of a dying disk where the last 1/3 of the disk took twice the time as it needed to scan the first 2/3 of the disk. We replaced the disk, and the user's problems mysteriously cleared up. This is why you should use the Manufacturer's utility to determine the continuing useability of any disk.

And, yes, defects do have a tendency to grow. As long as the growth is not due to oxide particles coming off of the platter surface you're probably ok.

Don't worry, be happy, just understand that all disks will fail. That's why your bank, and your government use RAID technology. And even then they sometimes get burned.

Popular Forums
icon
Computer Newbies 10,686 discussions
icon
Computer Help 54,365 discussions
icon
Laptops 21,181 discussions
icon
Networking & Wireless 16,313 discussions
icon
Phones 17,137 discussions
icon
Security 31,287 discussions
icon
TVs & Home Theaters 22,101 discussions
icon
Windows 7 8,164 discussions
icon
Windows 10 2,657 discussions

CNET FORUMS TOP DISCUSSION

Help, my PC with Windows 10 won't shut down properly

Since upgrading to Windows 10 my computer won't shut down properly. I use the menu button shutdown and the screen goes blank, but the system does not fully shut down. The only way to get it to shut down is to hold the physical power button down till it shuts down. Any suggestions?