life expectancy of a NAS if left on 24/7?

skanky

skanky

skanky

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wanting to use a NAS for storing media files used for streaming over a GbE lan, if stored in a cool environment, what sort of life expectancy can i expect from a NAS running all day, every day?
 
Surely leaving a hard drive on 24/7 would increase its life as (I could be wrong) I thought that when the hard drive recieves power thats where the damage comes from?
 
sid said:
i hope you don't believe that!

i'd say more like 3-5 years with intermittent use.
Click to expand...
Why?

They're industry accepted figures, you would be very unlucky for a drive to fail within 5 years of normal use and the electronics in the NAS itself will probably last a lot longer as there's no wear and tear.
 
MTBF = mean time before failure

in layman terms an average

if you look at a normal distribution curve - i.e. the bell shape. the mean is the center of this

you could get you drive, pug it in and it could last 1 second or theoretically if could last forever. both of these events are unlikely. its all just a question of probability, all you know is that 50% of the drives will fail before this time, and 50% after.
 
Yep, in all likelyhood if it doesn't fail within the breaking in period (first couple of months of 24/7 use I guess) then it'll likely last out it's useful life.
 
HEADRAT said:
Google know a thing or two about hard discs I would imagine, this is a very interesting read:-

http://storagemojo.com/?p=378

HEADRAT
Click to expand...

so so....

not relay that valid to be honest, 5 years is not enough 300,000 hour MTBFs = 12500 days or 34.2 years. tell Google to come back then with the results of there study.

EDIT: i also like the, ow the failure could be down to the controller line
 
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There are two things to consider.

1) Design life

2) MTBF

MTBF on it's own is a fairly poor measure since design life is not considered.

A fictional hard disk drive has a design life of 3 years. Provided I operate within this design life and replace the drive every 3 years the MTBF could be 1.2 Million hours.

This means that if I have a server farm with 1200 drives, 1 drive is expected to fail every 1000 hours (1,200,000 / 1,200) so I should expect to replace a drive every 42 days. I should also expect that 27 drives or 2.25% of the drives will fail in 3 years.

MTBF is ment to be applied to large populations with a defined design life. When the figure is applied to a single unit it can easily exceed design life by an order of magintude.

Personally the drive warranty is a good indicator of design life. Out of warranty = new drive.

"What does MTBF have to do with lifetime? Nothing at all! It is not
at all unusual for things to have MTBF's which significantly exceed
their lifetime as defined by wearout -- in fact, you know many such
things. A "thirty-something" American (well within his constant
failure rate phase) has a failure (death) rate of about 1.1 deaths per
1000 person-years and, therefore, has an MTBF of 900 years (of course
its really 900 person-years per death). Even the best ones, however,
wear out long before that."

http://www.ece.cmu.edu/~ganger/ece546.spring01/papers/mtbf.description

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As others have pointed out, MTBF is a purely theoretical figure (calculated using obscure numbers like the number of component parts that make up the drive). In the real world it's fairly meaningless. The gaurantee offered by the manufacturer is not much better, those offering a 5yr as opposed to 3yr might be thought of as better made drives, but in fact it's a marketing ploy. The company offering a 5yr warranty expects to sell more units based on the claim, charges a slightly higher price, and expects higher costs in servicing the extended warranty.

After an initial burn-in, the extent of the drive's remaining life depends on it's working environment (temperature and vibration being critical, but also how clean the power supply is). After about 5 years new developments in speed/capacity will have rendered the unit redundant anyway - so who cares after that period?
 
What you dont point out is that if the drive becomes obsolete due to technological advances in that 5 years the manufacturer usually replaces the dead drive with a better/larger one, so the 5 year warranty is still useful.
 
Talking real world, the most crucial factors are heat and usage. You are correct that leaving on 24/7 has some plus points - it avoids spin up/down which wears drives but it also increases time in use which isn't necessarily good.

Heat is key to HD lifespan. Keep it cool and it lives longer, Simple. Find a cool running drive (my experience is that Samsungs new F1 series run 5C cooler than every other brand I have tried - Seagate, WD, Hitachi) (and are very quiet, only Seagate equaling them on that front).

Then again if you are using a NAS, leave it on 24/7 and let it do other stuff for you while you sleep (web server, download box or whateve)... with no need for PC on.

I'm a NAS-a-holic now! :D
 
i'm a firm believer in leaving hard drives run 24/7, in fact i think systems in general are more reliable when left running.

in the many years i've been using boxes i've had a very small amount of gear die on me including hdd's and all my boxes run 24/7.
 
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