: Disk Utility can't repair drive, can drive be reformatted?


sashmo
Feb 2nd, 2014, 06:21 PM
I have a mid 2010 white unibody 13" macbook. Disk Utility can not repair this drive. Is it possible that the drive might be reusable if it is erased and reformatted?

eMacMan
Feb 2nd, 2014, 06:55 PM
This was fairly fully covered in your previous thread:
https://www.ehmac.ca/anything-mac/116754-disk-utility-gives-red-warning-need-reformat-drive.html
Condensed answer is: Very bad idea.

John Clay
Feb 2nd, 2014, 07:18 PM
I have a mid 2010 white unibody 13" macbook. Disk Utility can not repair this drive. Is it possible that the drive might be reusable if it is erased and reformatted?

As mentioned several times in the other thread, that drive is now worthless junk. Toss it and buy another.

pm-r
Feb 2nd, 2014, 08:48 PM
I have a mid 2010 white unibody 13" macbook. Disk Utility can not repair this drive. Is it possible that the drive might be reusable if it is erased and reformatted?


Before committing to any instant condemnation of the drive, I'd want to know just what and why DU said it couldn't repair the drive.

Was it some corrupt directory or some hardware failure?? If it was the latter, the drive is kaput.

If it's just some directory error, then either Diskwarrior or better yet, a nuke and pave with Disk Utility using its optional zero-out feature can recover such a drive.

As Mac support site says:
If a contemporary HD has a bad sector in it, one of the "tricks" used to force it to be mapped out is to use the security feature of Disk Utility or other tools to write zeros to the bad block. When the write fails, the controller in the HD remaps the sector to a spare sector, if there are any left.

Other such utilities such as Drive Genius can do the same thing and more.

Then test the drive for a while and don't rely on it for critical data, at least not right away.

John Clay
Feb 2nd, 2014, 09:51 PM
Before committing to any instant condemnation of the drive, I'd want to know just what and why DU said it couldn't repair the drive.

Was it some corrupt directory or some hardware failure?? If it was the latter, the drive is kaput.

If it's just some directory error, then either Diskwarrior or better yet, a nuke and pave with Disk Utility using its optional zero-out feature can recover such a drive.

As Mac support site says:
If a contemporary HD has a bad sector in it, one of the "tricks" used to force it to be mapped out is to use the security feature of Disk Utility or other tools to write zeros to the bad block. When the write fails, the controller in the HD remaps the sector to a spare sector, if there are any left.

Other such utilities such as Drive Genius can do the same thing and more.

Then test the drive for a while and don't rely on it for critical data, at least not right away.

It doesn't matter why DU can't repair it - it's not worth the risk that an underlying hardware issue is causing the directory corruption. Drives are cheap.

sashmo
Feb 2nd, 2014, 10:05 PM
Well, it was just a thought as the red repair flags did mention directory problems. Yes, I'm amazed how cheap drives are. Anyway, thanks for your quick responses.

pm-r
Feb 3rd, 2014, 12:33 AM
It doesn't matter why DU can't repair it - it's not worth the risk that an underlying hardware issue is causing the directory corruption. Drives are cheap.


I'm not suggesting that replacing a drive is not a good idea, just that it can be an overkill solution and how many take the time or bother to partition/format and zero-out a new drive to flag out any bad sectors? The factory sure doesn't do that with most consumer drives, and the Mac OS X is not perfect and can make mistakes.

Disk Utility has some good basic features but it's not exactly a high-end repair tool, and no doubt the reason that the Apple techs use such utilities as such as Alsoft DiskWarrior, Micromat TechTool Pro and/or ProSoft Drive Genius.

For the OP's benefit, a read through of the possible problem and fix may be found at:
The Repair functions of Disk Utility: what's it all about? (http://www.thexlab.com/faqs/durepairfns.html)

I don't know if the OP has even used the Disk Utility Repair Disk option at this point but may be an option for them to try. And maybe at least end up with a spare HDD for their use.

BTW: I was reading about Google's own hard drive department a week or so ago and they use similar utilities to resurrect a lot of their drives, and they have thousands of them to maintain and keep using. They also buy thousands of new ones regularly!!

eMacMan
Feb 3rd, 2014, 11:22 AM
The key part of all of this was that the drive had already shown a very noticeable loss of speed.

Obviously a corrupt directory could corrupt StopLight as well and that could certainly slow things down. Even if that is the entire cause, zeroing a large drive is going to take a fairly long time and the OP could well see his computer partially hobbled for over a day only to have the zero fail.

Then there is the issue of how much can you trust the drive? Maybe as an occasionally used offsite back-up, with a second drive just in case it goes flakey right after the main computer and back-up is stolen?

hexdiy
Feb 3rd, 2014, 12:18 PM
Exactly the kind of drive I put movies or music on. I can always get those back after a failure.

pm-r
Feb 3rd, 2014, 01:41 PM
I just realized that the OP's MB, if stock, just has a 250 GB (5400 RPM) HDD which wouldn't take too long to zero out and could be done while they sleep.

But if it was my Mac, I'd get and install a larger capacity Western Digital Scorpio Black 7200 RPM HDD if not a SSD, and then maybe stick the old drive in an external enclosure.

Result would be much better performance and a better quality new HDD at least. End of problem as well.

sashmo
Feb 3rd, 2014, 09:45 PM
Well, for what it' s worth, I erased the drive, stuck in my macbook startup disk and did a clean install of 10.6 on it. Not sure now if I'll take up to mavericks, which it previously had. I was just so amazed that it rebooted. Not sure if I'll use time machine again for backup as I've had some issues with it. I wish now that I had partitioned the big backup drive. I'd be interested in hearing what other people use for backups.

pm-r
Feb 3rd, 2014, 11:41 PM
Well if you were planning to keep using the drive, I'll say once again IMHO that it would have been worth your time to also zero-out the drive when you were erasing and partitioning/formatting it with the option to do so, so as to map out any possible bad blocks, just in case it had some.

And since you asked - my own choice for backups - CCC or it's full name - Carbon Copy Cloner. Period!!

sashmo
Feb 4th, 2014, 09:53 AM
Thanks for all of the comments pm-r. I did run the erase process several times. I'll look into CCC.

pm-r
Feb 4th, 2014, 01:22 PM
Thanks for all of the comments pm-r. I did run the erase process several times. I'll look into CCC.


Just to make sure we're on the same page, multiple "erase" are not enough.

When doing the erase options and setup, you should see a Erase Free Space button or maybe a ‘Security Options’ button that you need to click.

Then select the Zero Out option, the 7 step option is excessive IMO, and then let DU do its thing.

It's the Zero Out part that's critical and will map out any bad sectors.

If the drive is making any strange noises, it's kaput!! Replace it and take it apart and save the small but very powerful magnets for all kinds of uses. But keep them away from any small children!! :D

sashmo
Feb 4th, 2014, 04:37 PM
Nope, no strange noises.:)

hexdiy
Feb 4th, 2014, 05:41 PM
Chances are that drive is OK and bad sectors have been effectively remapped. But do you really want to run the risk? As I've posted before, mark it as second choice, or possibly hazardous if you will, and dump only non-critical data on it. Movies, music, anything not too difficult to get back. And enjoy!
And many thanks for recycling the planet!

broad
Feb 4th, 2014, 06:07 PM
cant wait for the follow-up thread in 3 weeks "help my drive is dead and I've lost __________. what do i do?"

sashmo
Feb 5th, 2014, 09:39 AM
Yeah, thanks for those kind thoughts broad. I do like recycling the planet though hexdiy.

pm-r
Feb 6th, 2014, 04:37 PM
Yeah, thanks for those kind thoughts broad. I do like recycling the planet though hexdiy.


We recycle as much as possible, but I also have several hard drives still in use and for several years now after they were zeroed out when DU exclaimed it couldn't repair them.

Others got recycled when the DU zero out failed - or if it was just good old dead!! Those motor magnets are super strong and very handy.

BTW: Diskwarrior was usually able to salvage 99% of the data from many of the DU stated "failed" hard drives.