On 03/18/11 19:41, Marcello Romani wrote:
> Il 18/03/2011 19:01, Mehma Sarja ha scritto:
>> There is one more thing to think about and that is cumulative aging.
>> Starting with all new disks is a false sense of security because as they
>> age, and if they are in any sort of RAID/performance configuration, they
>> will age and wear evenly. Which means they will all start to fail
>> together. It is OK to design a system and assume one or two simultaneous
>> drive failure - when the drives are relatively young. After 3 years of
>> sustained use, like email storage, you are at higher risk no matter
>> which RAID scheme you have used.
>>
>> Mehma
> 
> This is an interesting point. But what parameter should one take into 
> account to decide when it's time to replace an aged (but still good) 
> disk with a fresh one ?
> 
> Marcello

Well, a good start is to use something like SMART monitoring set up to
alert you when any drive enters what it considers a pre-fail state.
(Which can be simple age, increasing numbers of hard errors, increasing
variation in spindle speed, increasing slow starts, etc, etc...)


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  Phil Stracchino, CDK#2     DoD#299792458     ICBM: 43.5607, -71.355
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