how to tell if your hard drive is failing + needs to be replaced

[DieHard]

And the bad sectors are not dealt with by reformatting, because writing zeroes will result in reading zeroes successfully, promoting the bad sectors to good sectors.

I know I sound like a broken record...
but, If you can pull the drive and run the manufacturer's diagnostics in a windows PC, it will...
1) Scan every single sector (extended drive test)
2) Report after scan and ask if you want to "fix" bad blocks (mark,relocate, and update error map)
3) Report if the threshold of "too many" bad sectors is reached and determine if the drive is considered a "failure"

[OS923]

That was one of the first things that I tried. It's called Data Lifeguard Diagnostic for Windows. It found no errors.

[DieHard]

That was one of the first things that I tried. It's called Data Lifeguard Diagnostic for Windows. It found no errors.

Excellent

[OS923]

I tested all my hard disks.
http://www.gsehi.com/computing/problems/BadSectors.php
I use now only hard disks without bad sectors.

[DieHard]

I tested all my hard disks.
http://www.gsehi.com/computing/problems/BadSectors.php
I use now only hard disks without bad sectors.

From Diehard:

Get the data off, buy a new HD, and give the magnets to the kids or grand kids to play with from the old drive... they are so cool.  The point is, bad sectors usually lead to more (remember the old MFM, RLL days when we low level format... that was different technology, any SATA or PATA drive that needs low level formatting is ready for the trash, it should NEVER be done, it is on the way out, error mapping for the new technology drives is done at the factory... once)

Ahhh Cliff, I am glad you see the light

and don't forget to backup to OWC External FW RAID 1/Mirror (Like the Dual-Mini)
Here is the newer version (that you DON'T want) since it is eSata/USB
https://eshop.macsales.com/item/OWC/MEMDC2KIT/

Older version has FW400/800, Both use standard SATA Notebook drives

[OS923]

For my backups I consider working like this: I use Toast to save the Mac volumes to the FW400 disk as a disk image. I saw that this is really fast for OS 9. Then I use XP to copy them to a USB stick. USB sticks of 64 GB are now being sold in Belgium for under 20 euro. This can contain everything I saved on my Mac.

[OS923]

Apple System Profiler doesn't show my serial number anymore. It shows something like "  -  -000". Was this number stored on the HD that I replaced? Is there a way to reprogram this number?