Now anecdotical and off topic - was Re: [Beowulf] Re: Cooling vs HW replacement

Ariel Sabiguero asabigue at fing.edu.uy
Fri Jan 21 16:06:45 EST 2005


Robert G. Brown escribió:

>Has anyone observed that a megahour is 114 years?  Has anyone observed
>that this is so ludicrous a figure as to be totally meaningless?  Show
>me a single disk on the planet that will run, under load, for a mere two
>decades and I'll bow down before it and start sacrificing chickens.
>  
>
The longest lasting drives I have ever installed are still spinning 
since 1995 (I think back in june).
Those disks implement a RAID-1 on a Novell 3.12 and had been working 
24x7 since then.
I am aware that it is only 83K - 84K hours, but those NEC, 524 MB disks 
still astonishes me.
I thought that they would last at most 5 years..... I even wrote a 
letter by 2000 suggesting urgent replacement....
They survived a couple of power source explosions and the death of one 
motherboard.
They were installed when PC BIOS did not address more than 504MB and 
motherboard bios upgrade was too expensive...
The stepper bearings tolerated betwen 1,7x10^10 and 1,8x10^10 platter 
spins.... (if you check my figures, remember 3600 rpm, not 5400 and even 
less 7200 ;-) ).

Now I tend to believe that this company will continue adding servers, 
but never retire the old Novell.... (at least they retired the PCMOS one!)

In ten years now I will try to remember this and download the "R.G.B. 
Unplugged" video with the promised ritual.

Yours.

Ariel

PS: by the way, no cooling on those disks! Just environment temperature, 
which can reach up to 30ºC during summer in that office (don't make me 
remember what is like working there....).

>Humans don't live a megahour MTBF.  Disks damn sure don't.
>
>   rgb
>
>  
>

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