Internal HDD ejects itself / 'disappears'

[PliSsK]

The original 1TB HDD on my early 2008 8,1 iMac seems to be ejecting itself / disappearing when I am using Time Machine to save a large back up to it. The drive is about 8 years old and has been used daily for the first 6.5 years. It has spend 1.5 yrs in storage and was recently reinstalled into the iMac. I reformatted the drive and partitioned it. When performing a Time Machine back up (250GB) to the main 750GB partition, it gets to about 180GB then the drive disappears /ejects itself, and cannot be found in Finder or Disk Utility, even after rebooting. It only reappears on booting up the machine from cold the next day. If I try the TM back up again, the same thing happens (ejects at around 180GB). Disk Utility shows no faults on the drive and I've repaired it several times using Disk Utility in 10.11, and also tried recreating the partitions and erasing their contents. I saw a thread that stated that DiskWarrior was the only way to fix the corrupt file system on such a 'disappearing' HDD. What do you think? Or is it a hardware fault? I have backed up my data elsewhere obviously. Thanks in advance!

 

[PliSsK]

I downloaded a trial copy of DriveDx to analyse the hard drive and it seems it is down the slippery slope of failure, not sure if static during it's time out of the iMac caused the problem or not. Reallocated Sector Count (pre-fail indicator) 26 - indicator of possible problems with disk surface or read/write heads, the more sectors allocated (raw value), the worse the condition of the drive surface.

 

[Samuelsan2001]

TBH anything over 6 years is great for a spinning hard drive just replace it.

 

[mildocjr]

If you have data on the drive you can pull the drive out, put it in a zip lock bag (ensure no moisture in the bag), and throw it in the fridge for a few hours, while your waiting you might go out buy and new HDD and a SATA to USB adapter kit and install OS X on the hard drive. Once the old drive is nice and chilly (~about 3-4 hours) pull it out and connect it to the SATA adapter. Let the drive spin up and when it appears, start copying your /Users/<username> folder from the old drive to the desktop of your new drive. If you are lucky, you'll get it all copied.

Considering the issues you are facing, you probably have a bad sector on the disk, this may make it readable for a short time.

 

[PliSsK]

If you have data on the drive you can pull the drive out, put it in a zip lock bag (ensure no moisture in the bag), and throw it in the fridge for a few hours, while your waiting you might go out buy and new HDD and a SATA to USB adapter kit and install OS X on the hard drive. Once the old drive is nice and chilly (~about 3-4 hours) pull it out and connect it to the SATA adapter. Let the drive spin up and when it appears, start copying your /Users/<username> folder from the old drive to the desktop of your new drive. If you are lucky, you'll get it all copied.

Considering the issues you are facing, you probably have a bad sector on the disk, this may make it readable for a short time.

Thanks for the great tip! I will remember that for future reference. I had my data backed up elsewhere so I went ahead and did a 7 sweep secure erase of the whole HDD whilst it was still semi-operational which completed successfully. So now I can dispose of the HDD. It was indeed a sector issue (see 2nd post).