hard disk sentinel detect a raw read error 1 week ago but now it desaaperard how ??

[Yusuf Il]

how can that happen does my hitachi hard drive is ok ?

 

[Yusuf Il]

Any help

 

[Solandri]

A new HDD has several thousand or tens of thousands of extra sectors set aside as reserved. When a persistent read/write error develops in a regular sector, the drive's firmware marks that sector as bad and automatically substitutes a reserve sector in its place. Any future reads or writes which were supposed to go to the bad sector get seamlessly mapped to the reserve sector.

That's what the #5 Reallocated sector count is in your screenshot. It's the number of sectors which have been remapped this way. (Actually, it's probably a percentage of the reserve sectors which are used up this way.)

All this is normal, so a few such errors here and there are nothing to worry about. If your reallocated sector count starts going up by more than 10%-25% in a year, then you should start worrying. Sectors going bad that quickly usually indicates another problem with the drive. Likewise if you've got an old drive and its nearly used up all its reserve sectors (reallocated sector count approaching 100%), then you should consider replacing it before it reaches 100%.

 

[fzabkar]

AISI, an error RATE is something which can vary over time, ie it is a rolling average. OTOH, an error COUNT is something that increases over time, ie it is cumulative.

I don't know how Hitachi calculates its RRER attribute, but Seagate records the number of errors in each group of 250 million reads and then updates the normalised value of the attribute.