I wrote:

> If you're curious, smartmontools can be useful to extract substantial details 
> from the drive. It's not easy finding a binary package. I happen to have 
> PowerPC, Intel 32-bit and Intel 64-bit installers, built with MacPorts.

Email me offline if you want a copy. It's tiny. Easily emailed. Macports built 
the package installer and the DMG. The basic sequence is:

smartctl -s on /dev/disk0       [or whatever disk it is that you're interested 
in]

And then either:

smartctl -x /dev/disk0  [all plus extra information including temp tracking]

or 

smartctl -a /dev/disk0  [all information, as some drives don't support -x]


What I'll bet is you see a lot of ECC events, if it tracks them, lots of read 
errors, and pending sectors. The physicist who wrote smartmontools has 
elaborate documentation on how you can even locate each of the bad sectors and 
find out exactly what file or structure is located in that sector. And then how 
to try and read it and relocate it. It's very involved. Since it's just a TM 
backup, I'd just image it, and put it on a shelf.

You could try doing a short or extended offline test AFTER you have your 
backup. They are read-only tests, so they are non-destructive, but if the disk 
is dying the test could well send it over the edge. But might be useful if you 
do have a warranty claim to make with someone.

smartctl -t short /dev/disk0
smartctl -t long /dev/disk0

Upon hitting return it will tell you what time it will be done. I don't 
recommend checking until then. I do recommend going to Energy Saver and telling 
it not to spin down disks if possible. You don't want that happening while the 
test is occurring. I will say, in all cases of bad sectors I've had, neither 
short nor extended tests proceed terribly far. They get aborted by the firmware 
itself due to read errors it can't correct. And funny enough, this does NOT 
inherently qualify as a pre-fail category event! Nope, as far as the 
manufacturers are concerned, a certain percent of read errors are normal. Haha. 
So the only way to get past this is to zero the drive, which will thus remove 
the bad sectors from use entirely. So make sure you get a screen shot of the -a 
or -x option before you do a zeroing, as the next time you poll SMART it will 
show no more pending sectors (pending to be removed from use permanently) since 
once removed, they are no longer pending.

Anyway....


Chris Murphy
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