Bad Sector Count

At which point do you replace the hard drive? Is there a certain magical number of bad sector counts?

My Synology (DS1513+) just alerted me this morning that Drive Bay 1 has 4 bad sectors.

What’s considered a lot? What’s considered emergency change?


I don’t have an exact answer, but all I can say is replace it ASAP. I waited too long on my Synology and it basically crashed out on me. Don’t be me!

A bad sector count in my opinion is the early warning signal a drive is about to die.
I would replace it asap.

There was a time that you had a very good chance of finding some bad sectors on brand new hard drives. Bumping a drive or shutting down your computer improperly can cause them. That’s why Macs have disk first aid (& fsck) and windows machines have chkdsk, etc.

If bad sectors were found during routine maintenance, we would run a repair then continue to check the drive periodically. If there was no change, we left them in service. If errors started accumulating the drive was replaced. When I started a 1GB SCSI drive was around $1000. You just didn’t toss them out (assuming you had good verified backups).

If the cost is minimal, or if you don’t keep excellent backups, replace the drive. But whether you do or not, I suggest you monitor the system in case it was caused by a raid problem.