[ILUG] Why RAID

[Paul Jakma]

On Tue, 13 Jul 2004, Timothy Murphy wrote:

> I've been running computers at home for about 20 years,

> and in that time I have never had a total hard disk failure, by 
> which I mean a hard disk failure without warning in which it was 
> impossible to recover the data (or 99% of it).

Well, in nearly 20 years of running computers at home, I've had about 
3 or 4 fail on me. All SCSI strangely enough (but that's just cause 
majority of disks I've had have been SCSI) ;). Of the nearly 20 years 
i've had computers, mine have only had hard disks for about 10.

> This disk gave plenty of warning,
> as it slowly developed a kind of clicking disease.

Thing is, if you _work_ with computers, eg systems admin, you're 
quite unlikely to hear any clicking:

1. Sys admins dont usually sit in the machine room

2. Even if they did, they still wouldnt hear the clicking due to the 
general noise in a machine room (air-co, fans, etc.)

First thing you know is usually that the RAID controller has kicked 
the disk and is flashing the LEDs for the drive, or you get an email 
from mdadm or compaq's smartarrayd to say a disk had died.

If you believe disks are ultra-reliable, you simply have not worked 
with enough of them. They're as flaky as a very flaky thing sold by 
Kellogs. The most unreliable component in a PC by far, given their 
importance.

> Timothy Murphy

regards,
-- 
Paul Jakma	paul at clubi.ie	paul at jakma.org	Key ID: 64A2FF6A
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