[MacNNUK]

S.M.A.R.T. does it really give advance warning of drive failure in the real world ?

I have SmartReporter installed, and whilst it gives a useful RT when selftested, does SMART actually give you much advanced warning when it expects your HDD to have problems, or is about to fail ?

Currently I have 4,851 hours on my nearly 4 years old refurb iMac, with no HDD problems at all, averaging HDD usage of <4 hours per day.

ST3160812AS MTBF: 1,200,000 Hours !
So not expecting any problems sometime soon.

I sleep the whole iMac after 15 minutes idle, this rarely kicks in because I "sleep" whenever I leave the iMac, perhaps 6 times a day, and power down overnight, if nothing else for the self test when it reboots.

[Big Mac]

I think I've told you this before, but I think you're really overdoing the sleep and power cycling. 15 idle sleep isn't even something I do on a laptop. And there's essentially no need whatsoever to shut down every night. You're putting more wear on your hard drive with all the constant sleep cycles, so if drive longevity is your concern I'd say you're working toward the opposite effect.

SMART can predict a portion of hard drive failures. Some it will catch, while others it will not. If you really care about the SMART data you'll want to see the more detailed variables that a third party utility can provide, instead of the simple binary reading provided by Disk Utility.

[cgc]

I think the answer is "maybe." I had one instance where S.M.A.R.T. monitoring told me I had a problem but I had already noticed the problem (e.g. HDD was suddenly horribly slow). Wikipedia explains the "usefulness" of S.M.A.R.T.

[Spheric Harlot]

Originally Posted by Big Mac 

I think I've told you this before, but I think you're really overdoing the sleep and power cycling. 15 idle sleep isn't even something I do on a laptop. And there's essentially no need whatsoever to shut down every night. You're putting more wear on your hard drive with all the constant sleep cycles, so if drive longevity is your concern I'd say you're working toward the opposite effect.

Something learned from music studio work:

Mechanical components will tend to die from use (bearings especially).

Electrical components will tend to die from the voltage spikes during switching on/off the power.

(there's ongoing discussion about whether it makes more sense to power down aging/vintage synths, or to just keep them running all the time, with cost for electricity figuring against failure/repair frequency…)

[angelmb]

Originally Posted by Big Mac 

I think I've told you this before, but I think you're really overdoing the sleep and power cycling.
(…) You're putting more wear on your hard drive with all the constant sleep cycles, so if drive longevity is your concern I'd say you're working toward the opposite effect.

This.

Also of interest. Hard Drive Sleep

[shifuimam]

You didn't mention if you have a backup - if you don't I cannot emphasize enough the importance of setting up multiple backups of your most crucial data.

Your hard drive will fail. Even if it hasn't failed yet, and even if it is showing absolutely no signs of failure, you could turn on your iMac tomorrow and discover that your hard drive has catastrophically failed with no chance of any data recovery.

I have seen this happen many times. Don't rely on SMART status; don't rely on the current age of the drive; don't rely on a single backup or single copy of your data, period. Some hard drives fail over time, but some fail overnight.

[P]

We have discussed this here before, I think, but the gist of it is that some of the metrics (scan errors and bad/reallocated sector counts) are useful predictors, but that there are drives that fail without tripping any of the alarms. Manufacturers also hide some of the errors by setting the trigger values way too high. Other metrics (seek errors, power cycle counts, power-on hours...) are completely unrelated to future errors.

Google made a big study of it. It's well worth reading.

[MacNNUK]

Originally Posted by angelmb 

Also of interest. Hard Drive Sleep

Thanks

Originally Posted by shifuimam 

You didn't mention if you have a backup - if you don't I cannot emphasize enough the importance of setting up multiple backups of your most crucial data.

Your hard drive will fail. Even if it hasn't failed yet, and even if it is showing absolutely no signs of failure, you could turn on your iMac tomorrow and discover that your hard drive has catastrophically failed with no chance of any data recovery.

I have seen this happen many times. Don't rely on SMART status; don't rely on the current age of the drive; don't rely on a single backup or single copy of your data, period. Some hard drives fail over time, but some fail overnight.

I use TM, CCC and 1Tb external HDD's as backups.

Plus CD / DVD and USB Flash drive for important data, well covered.
(Yes, I used to be a PC User 20 years ago !)

Backups in different locations, including fireproof safe.

I even copy important folders, XL, financial, favorites, music, photo & video etc to another folder on HDD, plus daily Bookmarks, RSS Subs and Browser history etc (bitten after Onyx wiped my history, another thread elsewhere. )
Not to cover HDD failure, but sometimes I wipe apps etc I need a few days later !

On the 1Tb HDD every folder (140gb) is duplicated too. In case of bad sectors, not had any yet.

Originally Posted by Big Mac 

I think I've told you this before, but I think you're really overdoing the sleep and power cycling. 15 idle sleep isn't even something I do on a laptop. And there's essentially no need whatsoever to shut down every night. You're putting more wear on your hard drive with all the constant sleep cycles, so if drive longevity is your concern I'd say you're working toward the opposite effect.

The main reason I sleep, in my mind, is to extend the life of the backlight, however long that may be.
I'll take your advice on not powering down, that's been mentioned elsewhere too.

I wonder why, in the light of everything said above, Apple give the option of putting the HD to sleep whenever possible in Energy saver ?



Thanks to all for your comments.

[reader50]

I sleep my drives "when possible" and sleep the whole computer all the time. It is rarely turned off. My drives have rarely failed. They get rotated out in favor of bigger drives while still healthy.

My opinions on SMART:

If SMART indicates imminent failure, it is correct. No false positives. Backup NOW and change the drive.

If SMART indicates all is well, the drive may fail anyway. False negatives are a problem. Manufacturer alarm thresholds are sometimes too high - particularly on reallocated block counts. And SMART is not sensitive to some of the failure causes.

[angelmb]

Originally Posted by MacNNUK 

The main reason I sleep, in my mind, is to extend the life of the backlight, however long that may be.

Control-Shift-Eject puts your display to sleep.

[MacNNUK]

Originally Posted by angelmb 

Control-Shift-Eject puts your display to sleep.

Thanks, I also have Display Sleep as one of my Hot Corners.

Does it actually turn off the backlight ?

I notice it doesn't seem to invoke the screensaver, which doesn't turn off the backlight.

[chabig]

Originally Posted by MacNNUK 

The main reason I sleep, in my mind, is to extend the life of the backlight

That seems valid for older displays, but not the newer LED kind.

[MacNNUK]

Originally Posted by chabig 

That seems valid for older displays, but not the newer LED kind.

My display is 17-inch (viewable) widescreen TFT active-matrix LCD, 1440 x 900 pixels, millions of colors.

[OreoCookie]

Originally Posted by MacNNUK 

My display is 17-inch (viewable) widescreen TFT active-matrix LCD, 1440 x 900 pixels, millions of colors.

LCD stands for liquid crystal display which is a display panel technology while LED (= light emitting diode) stands for the type of backlight. Mostly, there are two choices of backlights these days: CCFL backlights (cold cathode fluorescent lamps) and LED backlights. LED backlights have a number of advantages (they don't need to warm up, they tend to be brighter and more energy-efficient). Judging from your screen specs, you have a CCFL backlight.

[cgc]

Now go stand in the corner until Big Mac tells you otherwise.