crystaldiskinfo reallocated sectors count fix

There is a 3 times rule in the drive's firmware - it reads a sector 3 times and if all 3 times it is bad then it may do a 'recalibrate' on the fly, and read 3 more times. This is all transparent to the outside world - except for the SMART util.Įach manufacturer can do as they please, so some set the error counts to zero, even though there might be 10 bad sectors as soon as the drive is manufactured. In fact they are 'logically swapped out' - the bad sector is mapped to a new, good, spare cylinder sector (it has spare cylinders - think of cylinders as tracks). So they map them out, this means the drive skips bad sectors. In the olden days, we had to enter the bad sectors in to the HDD controllerįrom a list on paper that came in the new drive box, so the controller skips them. There is no perfect HDD, never was, never will be, (history and fact). You will see how HDD's are made, tested and how they really work. I've attached an overview of the bad sectors reported by Disk Drill, and it doesn't look too bad, as I know drives can have bad sectors from the start.If you read the data sheets (white papers) say at

Opening the file after also worked, although it was really slow to open. I tried copy a 4GB file to the drive in Finder, and while it said 'preparing to copy' for about a minute, it appeared to successfully transfer. It then shows up in Finder, but right away Disk Drill reports that it has lost its HFS+ partition, and trying to search for it is unsuccessful. I have an external harddrive, which has been sitting underneath my Mac Mini, and I assume it didn't like the latter running Handbrake encodings for hours on end, because it has started failing a few months after I started doing that.Īfter trying to rescue files from it with Disk Drill (Which reported plenty of bad sectors), I finally gave up and reformatted it without problems using Disk Utility.

Crystaldiskinfo reallocated sectors count fix