🚀 go-pugleaf

"Unknown" <thisandthat@hereandthere.oz> wrote in message
news:FDv%b.61$S65.1164@nnrp1.ozemail.com.au...
>
> " Miro" <miro01@hotmail.com> wrote in message
> news:403e7c97$0$28870$afc38c87@news.optusnet.com.au...
> >
> > "Leythos" <void@nowhere.com> wrote in message
> > news:MPG.1aa7bde53e86577498a268@news-server.columbus.rr.com...
> > > In article <403DDBE5.67A77D68@ozemail.com.au>,
> > > audiobANTISPAM@ozemail.com.au says...
> > > > Scott Coutts wrote:
> > > >
> > > > > Yeah, sure. I dont doubt that it can be faster. But it's also true
> > that
> > > > > they can be slower... when all the motherboards started coming out
a
> > > > > while back with built in RAID controllers, people were going out
and
> > > > > setting up their RAID arrays and thinking how much faster it would
> > be...
> > > > > but those setups often just dont cut it (: They're OK for backup
> > > > > purposes I guess.
> > > >
> > > > RAID 1 generally offers higher performance than a single drive with
> > > > twice the risk of failure.
> > >
> > > RAID 1 is a mirror - two drives hold EXACTLY the same information.
While
> > > you have twice the chance for a drive to fail, you only have half the
> > > chance for data loss due to failure of any drive. In the real world
that
> > > means that loosing a single drive does not impact the user.
> > >
> > > RAID 0 is a stripe across two disks - this provides twice the chance
for
> > > mechanical failure and twice the chance to loose everything in the
event
> > > of a mechanical failure. Loosing either drive results in the complete
> > > loss of everything.
> > >
> > > RAID 5 is a stripe across 3+ disks with a parity stripe used to
rebuild
> > > the other drives in the event of a failure. In this situation you can
> > > tipple your chance for a mechanical failure, but you benefit from
being
> > > able to replace the defective drive and rebuild the entire array
without
> > > the loss of data. During the time a drive is lost, you will notice a
> > > significant performance hit.
> > >
> > > Mechanical failure does not always mean data loss - only RAID 0 in the
> > > example above suffers from data loss.
> >
> > Really, what happens if you blow two drives in a raid 5 setup ? Dont say
> it
> > never happens, it did.
> >
> >
>
> I'm still confused about those RAID answers. Why the hell cant you use a
> simple raid setup to have yet another HD attached to a computer and that
HD
> simply for backups? Eg, similar to having a Master on primary and a Master
> on Secondary off the motherboard. Thus, if C screws up and as you have
been
> good people and done backups all the time, just attach raid drive to
primary
> or secondary port, boot off Drive Image 7 CD (just for example, not that I
> am pushing the program) and restore. Buggered if I know why a suddenly
> scrambled C drive that wasn't scrambled because of a hardware fault would
> affect a raid mounted HD as suggested above.

I once spoke to a very sad IT manager. He had a mirror setup for his boot
drive. When the main drive started to wig out and write garbage the RAID
controller obliged by writing garbage to the mirror. Thus killing both boot
disks.

The magical assumption that a hard drive just dies isnt valid. It can do
some very strange things in the read/write cycle and cause no end of bother
on the data bus. Having said that, some software, such as databases also
likes to write pre-and post- cache files which require a stable read-write
cycle to marry up data changes. You can join the dots on the rest.