HDD Bad Sectors question...

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Level 3

714 points

HDD Bad Sectors question...

It happened like 3 months ago I had to shut down (via force shutdown i.e. holding the power button for over 3 seconds) my Mac after the system became un responsive during an empty trash operation. Then while running apple software update Windows (running Windows via bootcamp) it also locked up (it like completely froze no mouse movement at all). I would like to know if that created a bad sector in my HDD by doing this forced shutdown procedure. I reinstalled Mac OS X just to avoid any problems down the road after the forced shutdown.

Again the question is: Does a forced shutdown can create a bad hard drive sector?

Also, is there a way to recover bad HDD sectors? Disk Utility perhaps?

Thank You for your time.

2.53GHz Core i5 MacBook Pro 15" (Mid-2010), Mac OS X (10.6.4), 500gb HDD @ 7200rpm, 4gb 1067mhz ddr3 ram, Intel HD + Nvidia 330m 256mb

Posted on Oct 20, 2010 6:20 PM

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Answer 1

Kappy

Level 10

361,741 points

Oct 20, 2010 6:57 PM in response to vea1083

Abnormal shutdowns may destroy the drive's heads and/or severely scratch the platter's surface. That's sort of the worst case but what happens can be quite random. These can result in hard sector errors which cannot be repaired. Data in bad sectors cannot usually be recovered because the data are corrupted.

In your case you might try this:

Repairing the Hard Drive and Permissions

Boot from your OS X Installer disc. After the installer loads select your language and click on the Continue button. When the menu bar appears select Disk Utility from the Installer menu (Utilities menu for Tiger, Leopard or Snow Leopard.) After DU loads select your hard drive entry (mfgr.'s ID and drive size) from the the left side list. In the DU status area you will see an entry for the S.M.A.R.T. status of the hard drive. If it does not say "Verified" then the hard drive is failing or failed. (SMART status is not reported on external Firewire or USB drives.) If the drive is "Verified" then select your OS X volume from the list on the left (sub-entry below the drive entry,) click on the First Aid tab, then click on the Repair Disk button. If DU reports any errors that have been fixed, then re-run Repair Disk until no errors are reported. If no errors are reported click on the Repair Permissions button. Wait until the operation completes, then quit DU and return to the installer. Now restart normally.

If DU reports errors it cannot fix, then you will need Disk Warrior and/or Tech Tool Pro to repair the drive. If you don't have either of them or if neither of them can fix the drive, then you will need to reformat the drive and reinstall OS X.

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Answer 2

vea1083 Author

Level 3

714 points

Oct 21, 2010 8:03 AM in response to Kappy

Where in Disc Utility can I reformat my HDD? Does reformatting the HDD eliminate/repair bad sectors?

Thank you.

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Answer 3

Oct 21, 2010 8:25 AM in response to vea1083

While I suppose it's not impossible to damage the HD this way, I'd be very surprized. Holding down the power button to shut down is actually designed into the machine - Apple's own OS will instruct you to do this very procedure at times (eg. kernel panics) as a way of safely shutting down in the event the OS/system becomes unresponsive.

Baring an actual hardware failure of some kind, I think merely shutting down this way would be harmless. I've certainly had to do it countless times on many machines over the years when I worked with public machines in a university, and it never correlated with actual later hardware issues.

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Answer 4

Kappy

Level 10

361,741 points

Oct 21, 2010 8:39 AM in response to vea1083

See the following:

Extended Hard Drive Preparation

1. Boot from your OS X Installer Disc. After the installer loads select your language and click on the Continue button. When the menu bar appears select Disk Utility from the Installer menu (Utilities menu for Tiger, Leopard or Snow Leopard.)

2. After DU loads select your hard drive (this is the entry with the mfgr.'s ID and size) from the left side list. Note the SMART status of the drive in DU's status area. If it does not say "Verified" then the drive is failing or has failed and will need replacing. SMART info will not be reported on external drives. Otherwise, click on the Partition tab in the DU main window.

3. Under the Volume Scheme heading set the number of partitions from the drop down menu to one. Set the format type to Mac OS Extended (Journaled.) Click on the Options button, set the partition scheme to GUID (for Intel Macs) or APM (for PPC Macs) then click on the OK button. Click on the Partition button and wait until the process has completed.

4. Select the volume you just created (this is the sub-entry under the drive entry) from the left side list. Click on the Erase tab in the DU main window.

5. Set the format type to Mac OS Extended (Journaled.) Click on the Options button, check the button for Zero Data and click on OK to return to the Erase window.

6. Click on the Erase button. The format process can take up to several hours depending upon the drive size.

Reformatting can fix or remove bad sectors if there are soft errors. Hard errors cannot be repaired.

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Answer 5

vea1083 Author

Level 3

714 points

Oct 21, 2010 8:59 AM in response to Michael Black

Michael Black wrote:
While I suppose it's not impossible to damage the HD this way, I'd be very surprized. Holding down the power button to shut down is actually designed into the machine - Apple's own OS will instruct you to do this very procedure at times (eg. kernel panics) as a way of safely shutting down in the event the OS/system becomes unresponsive.

Baring an actual hardware failure of some kind, I think merely shutting down this way would be harmless. I've certainly had to do it countless times on many machines over the years when I worked with public machines in a university, and it never correlated with actual later hardware issues.

I thought the same. My computer became unresponsive when emptying the trash. I was not able to do anything not even a shutdown trough the Apple Menu, so I decided to shut it down by force (holding the power button). I did reinstall the OS but I don't recall formatting the drive, I did however click erase and then do a clean reinstall of OSX.

Here's another question, is it normal to hear my MacBook drive making a sound when starting up? is like churg, churg, but is very faint, you have to be like close to the laptop almost (your head has to be like 3 to 5 inches close to the HDD area of the laptop and in a quiet room. That noise is also done when opening apps but is less audible than in start up.

Thank You for your help.

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Answer 6

Kappy

Level 10

361,741 points

Oct 21, 2010 9:14 AM in response to vea1083

Snow Leopard's installer is smart. If a system is already present the installer does not erase the drive but installs a fresh system, moves all your stuff into the new system then removes the old one. To erase the drive you must first run Disk Utility from the installer's Utilities menu and use it to erase the drive.

The hard drive and the fans are both starting up at the same time. You may be hearing the fans and not the drive. If you're sure it's the drive making the noise but you don't hear more noise all the time, then it may be nothing. If you are hearing a sort of chirping noise coming from the drive that could be a sign of mechanical failure.

When you open Disk Utility and select your drive's main entry in the sidebar you will get the SMART status reported in the DU status area. If it doesn't say "verified' then the drive is failing. You can also run hardware diagnostics to check:

How to run hardware diagnostics for an Intel Mac

Boot from your original OS X Installer Disc One that came with your computer. After the chime press and hold down the "D" key until the diagnostic screen appears. Run the extended tests for a minimum of two or three hours. If any error messages appear note them down as you will need to report them to the service tech when you take the computer in for repair.

Some "common" error indicators:

SNS - sensor error
MEM - memory error
HDD - hard disk drive error
MOT - fan error

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Answer 7

Oct 21, 2010 9:28 AM in response to vea1083

There may well be some noise from the hard drive at startup. When you shut down, the hard drives are parked - literally pulled out of the way of the platters and parked so they cannot contact the drive. When you start up, they unpark - again, lift up and move into position over the platter surfaces, ready to read/write. The action of parking/unparking drive heads often causes a noise, some drives being much louder than others.

Other then some low pitched whirring though, your drive should not be making much of any noise once the system has booted up.

And drives will also park when sleeping (and, obviously, unpark when waking), or when directed to do so by the motion sensor. So, if you have not had any disk activity for awhile, your drive may sleep and park the heads. Then when you launch a program and thus initiate a bunch of disc I/O, you may hear the drive heads unparking.

As mentioned, the noises to worry about would be constant things like chatter or buzzing, which are often prelude to a drive spindle failure. Or, if you heard the drive heads continually parking and unparking, that would not be good (a bad motion sensor can cause that).

Using the power button as you did is the proper way to deal with a frozen system - yanking the plug/battery is NOT something you ever want to do (and yet, sometimes, people still do).

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Answer 8

vea1083 Author

Level 3

714 points

Oct 21, 2010 9:52 AM in response to Kappy

Kappy wrote:
Snow Leopard's installer is smart. If a system is already present the installer does not erase the drive but installs a fresh system, moves all your stuff into the new system then removes the old one. To erase the drive you must first run Disk Utility from the installer's Utilities menu and use it to erase the drive.

The hard drive and the fans are both starting up at the same time. You may be hearing the fans and not the drive. If you're sure it's the drive making the noise but you don't hear more noise all the time, then it may be nothing. If you are hearing a sort of chirping noise coming from the drive that could be a sign of mechanical failure.

When you open Disk Utility and select your drive's main entry in the sidebar you will get the SMART status reported in the DU status area. If it doesn't say "verified' then the drive is failing. You can also run hardware diagnostics to check:

How to run hardware diagnostics for an Intel Mac

Boot from your original OS X Installer Disc One that came with your computer. After the chime press and hold down the "D" key until the diagnostic screen appears. Run the extended tests for a minimum of two or three hours. If any error messages appear note them down as you will need to report them to the service tech when you take the computer in for repair.

Some "common" error indicators:

SNS - sensor error
MEM - memory error
HDD - hard disk drive error
MOT - fan error

Just to clear myself up. When I clicked the "erase" (in Disk Utility) button when I reinstalled OSX 3 months ago on my MacBook Pro, it said in the Disk Utility Progress bar un-mounting image, it took like two minutes. Then I went to install OSX and I had to reinstall iLife, and the rest of my third party apps, so that's why I think I did a clean reinstall.

However, this question of bad sectors came to be because one close friend of mine told me that I damaged my HDD by doing the hard shutdown method (Power button 3-second hold), which of course concerned me. I think I might go ahead and do the zero out disk option when I do reinstall OSX again in the future. As far as disk utility goes, it says that my SMART status is "veryfied" I did also used OnyX SMART status veryfication and it turned out to be ok. I think that I am best off keep using my MacBook Pro until it requires a new OS reinstall or an HDD failure.

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Answer 9

Kappy

Level 10

361,741 points

Oct 21, 2010 10:12 AM in response to vea1083

Yes that sounds like you erased the drive prior to installing.

Now, don't run off and re-do everything if your computer is running fine. For future reference, however:

1. If you shutdown the computer abnormally or if the computer shuts down abnormally due to power outages, brownouts, or any other abnormal ways, then immediately boot from your installer DVD and use Disk Utility to repair the hard drive and permissions. There is no way to know whether an abnormal shutdown will cause any damage, but doing the repairs ASAP may fix things before any further damage is done.

2. Keep up to date backups of your hard drive, and backup the backup. You can never have too many backups but you sure can have too few.

Have at least one of those backups be a bootable clone of your known good boot drive.

3. If you must reformat your startup drive due to an abnormal shutdown problem, then use the Zero Data (one-pass) option to assure that all the sectors on the drive are good. It takes time but better safe than sorry.

4. Keep your system maintained. Download and install AppleJack - VersionTracker or MacUpdate. Read the docs so you know how to use it in case you have to. If you notice your computer is starting to slow down - perhaps notice those beachballs a little too oftern - run AppleJack per its instructions. It may clean things up.

5. Don't repair permissions unless you are getting permissions error messages. Doing so otherwise is unnecessary except before installing a system update then repair both hard drive and permissions before downloading and installing. Good preventative.

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Answer 10

Oct 21, 2010 11:24 AM in response to vea1083

"However, this question of bad sectors came to be because one close friend of mine told me that I damaged my HDD by doing the hard shutdown method (Power button 3-second hold), which of course concerned me."

Your friend told you wrong. That procedure is in your user manual. It is the officially proper means of shutting down a unresponsive system (in the "Proeblem, meet solution" portion of the user guide). I think it is no different from shutting down from the command line "shutdown -h now", which properly powers off the hardware.

Unless your hard drive was already experiencing a failure or problem of some kind, that shutdown is a non-issue.

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Answer 11

Kappy

Level 10

361,741 points

Oct 21, 2010 12:09 PM in response to Michael Black

It is the proper method of shutting down an unresponsive machine, but it is still an abnormal shutdown that may damage data as well as the drive itself given the right circumstances. Doesn't mean it will happen; it simply means it may.

The reason the procedure is described in the user manual is because it is the only way to shutdown the computer when it becomes unresponsive.

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Answer 12

Oct 21, 2010 12:19 PM in response to Kappy

Kappy, why do you call it an "abnormal" shutdown? I can appreciate that it is only elicited by some problem with the system, but I don't consider the shutdown itself to be abnormal. It's my understanding that it merely triggers a firmware directed power down and system halt which in terms of powering off the hardware is a perfectly normal shutdown.

It's just manually doing the last thing the OS would initiate if you had selected "shutdown" from desktop.

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Answer 13

Trisha K

Level 1

19 points

Oct 21, 2010 12:48 PM in response to Kappy

Hi Kappy,

Sorry for jumping in... Just for clarification, say I have a late 2008 MacBook Pro that came with Leopard, but Ive since upgraded using a retail Snow Leopard disc - Which disc should I use for Repairing the Hard Drive and Permissions (the original install disc 1 or the retail Snow Leopard disc)?

Thanks as always for your essential advice!

😉

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Answer 14

eww

Level 9

53,028 points

Oct 21, 2010 12:53 PM in response to Trisha K

Always use the installer disc for the most recent major OS version that is installed on the machine.

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Answer 15

Kappy

Level 10

361,741 points

Oct 21, 2010 1:33 PM in response to Michael Black

An abnormal shutdown is one that does not involve selecting Shutdown from the menu or pressing the power button (if you have one) on the keyboard or pressing the Power button and selecting Shutdown from the dialog. Holding down the Power button for 5-10 seconds forces a shutdown without the benefit of having the OS and/or the drive finish uncompleted disk transfers. The hard drive has an onboard cache. If the cache is both read/write enabled as they mostly are then the cache needs to be flushed before the drive is turned off or there could be data in the cache that hasn't made it to the platter. The OS also maintains its own disk cache which is periodically flushed to the drive. If that doesn't occur then again data may be lost.

When the machine is completely locked holding down the Power button cannot proceed with a normal shutdown, hence it's an abnormal one.

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