🚀 go-pugleaf

" Miro" <miro01@hotmail.com> wrote in message
news:403f388e$0$20139$afc38c87@news.optusnet.com.au...
>
> "Unknown" <thisandthat@hereandthere.oz> wrote in message
> news:seG%b.165$S65.6424@nnrp1.ozemail.com.au...
> >
> > " Miro" <miro01@hotmail.com> wrote in message
> > news:403ea6bb$0$19707$afc38c87@news.optusnet.com.au...
> > >
> > > "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.
> > >
> >
> > It's pretty damned obvious why a real time 100% of the time backup would
> > stuff up if you mirror C elsewhere and expect elsewhere to work
> continuously
> > every single time when C fails.
> >
> > > The magical assumption that a hard drive just dies isnt valid. It can
do
> >
> > Rot. I have had that happen even to my own computer. Back when 20gig was
a
> > medium sized drive, I had 2 and C died in 6 weeks. By then 40gigs were
> about
> > and I bought a 40gig for C drive and restored from backup. No problems.
> What
> > I do is have the other drive as a backup drive only where mirror images
> are
> > stored but as my data doesnt have to be correct to the nanosecond, I
only
> do
> > mirrors 2 times a week (auto). I have compressed images on that drive.
HDs
> > DO just die and saying they dont is just plain wrong.
> >
> > > 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.
> >
> > Sure. That goes back a long way. I remember old 5.25 drives where you
> write
> > something to it and wait. The drive light had to go out then let 30
> seconds
> > pass and it would come on again for a few seconds and go out again. THEN
> you
> > could remove the disk. Doing it before that ended in dead data. However,
> > what you said doesnt have any relevance to the last sentence of what I
> > posted above.
>
> Look at it this way. Some hard drives just curl up and die, others flop
> around like B-grade actors and just cant seem to get the whole death thing
> into perspective. Admitedly sudden death is far more common, but not the
> only style of data decapitation.
>
>

Nothing to do with what I said above, a few letters back though....

A HD can die on a raid and not affect any other HD.