[nylug-talk] How to set up Raid 1 on Ubuntu, Or Linux in gerneral

[alex at pilosoft.com]

On Fri, 1 Jun 2007, Henning Follmann wrote:

> 
> On Jun 1, 2007, at 2:08 PM, sixtyfourbeets wrote:
> 
> >
> > Convention dictates that when constructing a true SAN one should buy
> > drives from different manufacturers.  Doing so addresses the concern
> > that a particular drive will not be the same as the next drive in the
> > SAN.  The reasoning behind that is if drives are from different
> > manufactures chances are less likely that the drives will fail in a
> > similar fashion in a reasonably short time span.
> >
> > Steve M
> 
> Sorry there is no reasonable logic in what you just wrote.
> 
> Do you seriously think that two hard drives because they are built on a
> same day in the same place will fail also on the same day? I think it is
> more likely two win twice in the lottery in the same week with the same
> numbers.
Unfortunately, even the worst trolls are occasionally right. Yes, drives 
from same batch often fail concurrently. IE. the correlation between 
failure times on same batch is non-zero. 

There are some papers on that too.
-alex