9 errors after surface scan - need to reformat?

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Level 1

134 points

9 errors after surface scan - need to reformat?

Ran a surface scan using TechTool Deluxe -- 3.0.4 -- on my internal 250GB Maxtor HD. It reported 9 errors and suggested I reformat the drive.

Are 9 bad blocks a worrisome enough number to justify the time to reformat the HD and move everything back from the external backup drive? If so, is a reformat enough of a fix or do I need a third party disk repair tool?

Thanks in advance.

20 iMac G5 (Rev A), Mac OS X (10.4.3)

Posted on Nov 17, 2005 5:21 AM

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Answer 1

PJB

Level 2

365 points

Nov 17, 2005 5:38 AM in response to Just Jim

Just Jim, sorry to be the bearer of bad news, but to the best of my knowledge, surface errors usually mean that the drive is physically damaged and (alas) unrepairable. Apparently these errors multiply over time, so your best bet is to back up your important data and start saving for a new HD. Unless you are still under guarantee!

Best of luck.

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Answer 2

Jim S

Level 4

3,464 points

Nov 17, 2005 6:04 AM in response to PJB

Jim PJB could and probably is correct. However, if you are still under warranty, contact Apple via the G5 iMac chat room.

It is availble via these discussion boards in the iMac G5 section. It is the first selection.

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Answer 3

Just Jim Author

Level 1

134 points

Nov 18, 2005 7:58 AM in response to Jim S

I'm not sure what this means but, last night, I booted from my cloned external drive and used Disk Utility to erase the internal drive. I zeroed out the data. Then, from the external drive, I did another TechTool surface scan of the internal HD. And I got zero errors.

I copied all my data back to the HD and things seem to be as they should!

(So I guess that TechTool's "surface errors" are not necessarily irreparable physical damage. . .)

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Answer 4

Jim S

Level 4

3,464 points

Nov 18, 2005 8:15 AM in response to Just Jim

Glad the problem was solved!

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Answer 5

Chris CA

Level 10

82,513 points

Nov 18, 2005 9:00 AM in response to Jim S

surface errors usually mean that the drive is physically damaged and (alas) unrepairable.
Which is why bad blocks get mapped out by the OS and disk utilities.
Every single drive ships with bad blocks. They are mapped out at the factory.

Apparently these errors multiply over time, so your best bet is to back up your important data and start saving for a new HD.
Well, yeah but since a 160 GB Mac OS Extended volume has a default block size of 4 KB and has 40 million available blocks, 9 bad blocks is literally not even a gnat.

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Answer 6

PJB

Level 2

365 points

Nov 18, 2005 6:38 PM in response to Chris CA

"Apparently these errors multiply over time, so your best bet is to back up your important data and start saving for a new HD."
"Well, yeah but since a 160 GB Mac OS Extended volume has a default block size of 4 KB and has 40 million available blocks, 9 bad blocks is literally not even a gnat."

Yes, Chris, that is quite true. However, the surface errors could indicate a more serious problem with the drive, especially if those bad blocks happen to contain some important information.

I don't want to sound like a doom monger but that is exactly what happened to me with my XP laptop. Which is why I now own a Mac!

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