Soft Read Error Rate for Hard Drives

Question

I am currently testing many hard drives (with gsmartcontrol). My goto, rule of thumb of detecting a defective hard drive is to look at the Reallocated Sector Count and the Current Pending Sector Count.

However, with one hard drive, the Reallocated Sector Count and the Current Pending Sector Count read 0, but another metric, Soft Read Error Rate is highlighted and reads 4.

How do I interpret such data? What are soft read error rates, and with them, are hard drives considered defective?

Solution

What are soft read error rates

Soft errors are errors that went away when your disk retried an operation. A small number might be caused by minor electrical glitches and is no direct cause for worry.

with them, are hard drives considered defective?

No. The 4 problems were transient, and probably did not last for more than a second combined.

Comments

[Synetech]

Have you rebooted since you saw it? Try shutting down (actually powering off) and then see what the value is the next time you start up. Depending on how your drive’s manufacturer implemented that value, it may be reset to zero.

[Admin]

@Synetech I ran a hard drive test, and it was reset to zero.

[Synetech]

That makes sense. It indicates that it received a request, tried to read, couldn’t, reported to the OS, and tried again. If there’s no change to the other values you listed, it obviously managed to read it when it tried again. That could mean that the sector is bad (especially if it happens several times—e.g. four), in which case it will eventually relocate it, but if it was once or twice, it could have been explained by other means and likely ignored safely. If you did a full test and it came up clean, then it was probably something like a dip in the power-supply or humidity or cosmic rays.

[Admin]

Other than suggesting cosmic rays ;), good info....thanks.

[Synetech]

Technically, cosmic rays are legitimate source of electronic errors, assuming of course that the errors are not consistent or reproducable.

[Admin]

+1 Good info. I did a full scan of the hard drive, and it succeeded.