Re: [patch] document flash/RAID dangers

[Chris Adams]

Once upon a time, Alan Cox <alan@xxxxxxxxxxxxxxxxxxx> said:
> > The issues being raised here are not specific to extX, MD RAID, or Linux
> > at all; they are problems with non-"enterprise-class" RAID setups.
> > There's a reason enterprise-class RAID costs a lot more money than the
> > card you can pick up at Fry's.
> 
> And you will still need backups ;)

Yep.  RAID (of any class) != fail safe.

> A long time ago I worked on a fault tolerant news server with dual
> alphaserver boxes and a shared disk array. A power system failure took
> out both the alpha boxes and the disk controllers and all the disks.

Hey, that's not funny!  I'm typing this on a dual AlphaServer cluster
with a shared disk array (with dual battery backup even), and we had a
power failure at the NOC yesterday (that then tripped a breaker,
although it was between the generator and the UPS, so nothing went
down).

No matter how redundant you make things, a "no single point of failure"
setup still can fail, often in "interesting" ways that nobody
anticipated.

-- 
Chris Adams <cmadams@xxxxxxxxxx>
Systems and Network Administrator - HiWAAY Internet Services
I don't speak for anybody but myself - that's enough trouble.
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