Just how reliable is SMART status?

[weckart]

I upgraded my Macbook's HD to a WD2500BEVS last year. Yesterday, I noticed in Disk Utility that my HD was in red with a warning that my HD's SMART monitor was reporting an imminent failure. Up to then, I had had no inkling that anything was wrong. No read/seek errors or slowdowns, no clicks. Nada.

I immediately backed up all my data and checked again. Still the same imminent failure report. Checked with Tech Tool Pro. Same thing. Drew a deep breath and rebooted. No problems or delays on restarting. Same warning.

Checked on the internet. Seems to be lots of SMART failures with this particular disk. Time to send it back.

My disk was within warranty, so I got an RMA from WD UK. I would have to send my disk back to them at my expense within 30 days of receipt of the replacement or I get stung for twice its market value ($198 - ).

Later today, I check again. The SMART status has changed to normal. Check again with TT4. Passes all disk tests with flying colours. Huh?

Now I know it is best to err on the side of caution, so I am not looking for replies with "back your data up, dude and send it back" for that is what I have done.

Does anyone have experience of this warning of disaster and dire combustion and yet find his/her disk working regardless? In other words, are WD's prone to giving false positives on the SMART warnings? I might end up having to send back my disk time after time if that is the case.

 

[gr8bob]

I upgraded my Macbook's HD to a WD2500BEVS last year. Yesterday, I noticed in Disk Utility that my HD was in red with a warning that my HD's SMART monitor was reporting an imminent failure. Up to then, I had had no inkling that anything was wrong. No read/seek errors or slowdowns, no clicks. Nada.

I immediately backed up all my data and checked again. Still the same imminent failure report. Checked with Tech Tool Pro. Same thing. Drew a deep breath and rebooted. No problems or delays on restarting. Same warning.

Checked on the internet. Seems to be lots of SMART failures with this particular disk. Time to send it back.

My disk was within warranty, so I got an RMA from WD UK. I would have to send my disk back to them at my expense within 30 days of receipt of the replacement or I get stung for twice its market value ($198 - ).

Later today, I check again. The SMART status has changed to normal. Check again with TT4. Passes all disk tests with flying colours. Huh?

Now I know it is best to err on the side of caution, so I am not looking for replies with "back your data up, dude and send it back" for that is what I have done.

Does anyone have experience of this warning of disaster and dire combustion and yet find his/her disk working regardless? In other words, are WD's prone to giving false positives on the SMART warnings? I might end up having to send back my disk time after time if that is the case.

I have no idea how reliable WD drives are these days. They seems to have a mind of their own. I own the WD3200BEVT 320GB Scorpio drive instead of the 250GB. Just before I sent it in to the Apple techs, the SMART status reported just fine.. today, I called them up to check on the status (it's been a friggin week and they've just started looking on my machine) and the guy told me that my drive's giving off a SMART failure status.

I don't know what annoys me more considering that I've never moved the drive while it's spinning -or- the fact that the tech guy told me hard disk failure causes graphic/display glitches.

 

[weckart]

Errrgh. I did not want to hear that. I put in that very same drive into my Macbook Pro last week. Contrary to all the guides, opening that baby was anything but a piece of cake. I really do not want to have to open that again because WD cannot get its act together. Damn. Should have held out for the Samsung M6.

 

[2112]

Just how reliable is SMART status?

Very.

More info on S.M.A.R.T. here.

 

[weckart]

Your link contradicts your assertion that SMART is 'very' reliable, but thanks for googling.

Many motherboards will display a warning message when a disk drive approaches failure. Although an industry standard among most major hard drive manufacturers,[11] there are some remaining issues and much proprietary "secret knowledge" held by individual manufacturers as to their specific approach. As a result, S.M.A.R.T. is not always implemented correctly on many computer platforms due to the absence of industry-wide software & hardware standards for S.M.A.R.T. data interchange.[citation needed]

On the basis that real life empirical testing > Wikipedia, any day, I was really after specific examples, particularly with Scorpio drives.

 

[rhyx]

Return the drive. I've had SMART failures disappear and then come back before. Or more frequently I have a SMART warning and then the drive dies soon.

 

[alphaod]

In the one time I had a SMART notice, I backed up the drive and then it failed, so now I believe the notice.

 

[zorinlynx]

A SMART failure means the disk is on its way out. Replace it immediately. And verify your backups, as you may need them. A SMART failing disk tends to fail completely DURING that last backup, in my experience, so don't overwrite your CURRENT backup with the failing disk.

It doesn't work the other way around, though. In fact, most disk failures I've had showed no SMART anomaly before they occurred. The disk just died and I had to replace it. Out of about six total personal disk failuers in my life time, only *one* had a SMART warning before it failed. And it literally ended up failing within the next hour.

So yes, send it back.

 

[wxboss]

WD drives have a pretty good track record these days. Your particular drive received good reviews on Newegg. Yet, if you are getting a SMART error, I would start damage control procedures immediately.

 

[lhotka]

It's not. Google's massive study on hard drive reliability essentially concludes that "SMART isn't".

There was a great podcast from Steve Gibson (Spinrite) and Leo Laporte on this (available on iTunes at one point) that discusses this in detail.

 

[quagmire]

It didn't indicate my 12" Powerbooks HD failing when it did back in January.

 

[2112]

Your link contradicts your assertion that SMART is 'very' reliable, but thanks for googling.

Indeed, allow me to expand.
From what I understand and from experience, the standard protocol problem is that SMART takes into account a great number of sensors and statistics and vendors haven't agreed on which ones to use, however, once SMART reports that a disk is about to fail, it will certainly do so (and this is what I meant with 'very').

cheers