Re: What is the point of RAID?
On Tue, 11 Nov 2008 19:54:11 -0600
Mark Allums <mark@allums.com> wrote:
> that three drives is 50% more likely to fail than two. More than
> fifty percent, if I remember my statistics at all correctly.
Do you mean it is more likely that any one drive in the array fails when
you have more drives, or do you mean that it is more likely for a drive
in the array to fail when you have more drives? If drives fail more
often when being used in an array with more drives, what makes them
fail more often under those conditions?
> If you
> have a RAID 50 running on 20 SAS drives and 4 hot spares, you better
> buy quite a few for cold spares, you are going to lose a drive every
> two months. At least.
You are saying that the age of the drives doesn't matter at all? Then if
you lose one drive out of 24 every month, that would mean that about 4%
of all drives sold are junk. The new ones you get could fail within the
first few minutes ... or not work at all. Or does this mean that it
takes about one to two months before you find out if a new drive is
junk? And why don't the drives that are junk fail in the first few
minutes or don't don't work at all?
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