High S.M.A.R.T read error rate

I have a Seagate ST9750420AS HDD in my laptop, which I have been using for the last couple of years. I recently realized that the disk was noticeable slower than before, so I decided to check the SMART data.

Everything seemed to be OK. A bit more than a year powered on, head flew for 11 months... and all the read errors successfully corrected; no big deals. I decided to note anyway the read error rate, which had a value of 60M (normalized 119, threshold 6, worst 99).

Today (3 days after), I checked again those numbers and the read error rate value is at 215M, which seems to me like a huge increase in a little time. The normalized and worst values haven't changed anyway, so the assesment is still OK in the SMART data.

Should I be worried? My data is backed up, but should I be already buying a new HDD for my laptop?

Peque

Posted 2015-01-21T22:09:01.563

Reputation: 721

It may be simply a loose connection. Try to disconnect the HDD and install it again. – gronostaj – 2015-01-21T22:15:32.777

@gronostaj: The HDD is mounted with screws, but anyway I will try that. Thanks! :-) – Peque – 2015-01-21T22:29:39.820

There has to be some type of data connection. 215 million errors is not normal. Be sure you understand how S.M.A.R.T should be read it snot always obvious.

– Ramhound – 2015-01-21T23:37:46.667

The raw value isn't very meaningful by itself, and not very reliable to predict any failures. If the normalized value is above the threshold, you're fine. Keep your backups up to date, that's all. – Pedro Werneck – 2015-02-21T15:43:17.673

@PedroWerneck: I forgot about this question. I've updated it with my own answer to "close" this topic. :-) – Peque – 2015-02-21T19:45:47.800

1215 million errors is perfectly normal and an inherent part of how modern hard drives operate. Most drives will however hide all errors from you if they can correct them - Seagate is the notable exception here. The raw value before error correction is an internal performance metric used by the hard drive firmware and not meant to be of value to the end user. That said, if you have access to the detailed technical specifications for the drive, you can draw meaningful information from it but it needs to be refreshed every second because counter resets in a matter of minutes. – qasdfdsaq – 2015-10-18T20:06:48.927

Answers

After some time, I can confirm that the raw read error rate value isn't very meaningful nor reliable. I have seen this counter reset to 0 more than once since I posted this question. And although the normalized value has decreased, it is still way above the threshold.

The reason why I posted this question was because I started to realize that the HDD was noticeable slower than before. Opening the file manager could take even seconds, as well as opening other programs or files. And I could hear the HDD "struggling" and making noise as trying so hard to read just a couple of bytes (and could see the raw read error rate increase a lot just after any of those operations...). Formatting didn't help with that anyway. Ensuring the HDD was correctly connected and the connector was clean didn't help either.

Why was this happening? I don't know, but I ended up buying a small SSD to replace it and use the HDD as a secondary drive (for data only). That increased my productivity at work and my health too... :-P (hearing my HDD struggling for reading data was making me sick)

As a conclusion: the raw read error rate is not meaningful by itself. The HDD seems to be working fine still, and it will probably continue to work for another couple of years, although it continues to be slow (something that does not bother me while the OS is on another disk).

My personal recommendation: always make backups even when your disks are healthy and brand new. If you feel your HDD is getting slow, consider buying a SSD to put your OS on it. They are pretty affordable nowadays and, if you use your computer a lot (i.e.: you work full time with it), then you'll really notice the difference.

Peque

Posted 2015-01-21T22:09:01.563

Reputation: 721

It's both meaningful and reliable, but like ALL raw values it's meaningless to end users who don't understand it. It's manufacturer proprietary and what it means is understood only by the manufacturer. – qasdfdsaq – 2015-10-18T20:01:42.480

-1

My experience with slow HDD and SMART is when the value of "reallocated sector count" is above zero. Sometimes it helped to write the WHOLE disk with zero eg.:

dd if=/dev/zero of=/dev/<drive> bs=4m

Of course you will loose the data on the disk and it may take a while. I actually have a disk with a "raw read error rate" of above 80k that was connected via USB 3.0. It seems to work though.

B. Walger

Posted 2015-01-21T22:09:01.563

Reputation: 1

1This question was about Seagate's raw read error rate which is a somewhat known issue with SMART programs. It is a rolling sector count that goes back to zero after 250 million. To this day I don't think I've seen a SMART program display this correctly in a "normalized way", aside from Seagate's own Seatools. – DocWeird – 2017-11-29T09:41:12.317