Laurie,
spanning: The drives are cascaded. So if you have a 60GB and 80GB HD
you get a 140GB HD. Except that you are able to see one big HD there is
no advantage regarding speed, etc.
striping: Puts drives in parallel configuration. The smallest HD limits
the capacity. For example if you have a 60GB and 80GB HD then the total
capacity will be 60GB*2=120GB. The advantage is that you can almost
double the sustained read/write speed. This is only true if the drives
are on seperate IDE channels. Most motherboards have two independent
channels. In this configuration you are best off using two identical
HDs.
mirroring: Writes the same data on two different drives. So when one
goes bad you can replace it with the other. You don't gain any capacity
or speed if it is not combined with any of the above techniques (which
then will require more then 2 HDs).
If you have raid0+1 you use striping and mirroring. So if you have 4
60GB HDs you would have 240GB with striping (RAID0) only. But since you
use also mirroring (RAID1) the capacity is only half of it to keep a
copy of all the data you have -> 120GB
Robert
--- LAURIE SOLOMON <LAURIE@ADVANCENET.NET> wrote:
> Preben,
> Since you seem to be knowledgeable about IDE RAID matters, I wish to
> make
> use of your knowledge as a resource even if it is OT for this list.
> I
> recently bought an ABIT motherboard with RAID. The manual is not
> very clear
> as tot he difference between RAID 0 (striping) and what it does
> versus JBOD
> (spanning). I understand what RAID 1 (mirroring) is and how it
> works; but I
> really do not understand how RAID 0 works or what parallel operation
> of the
> two drives on the channel means and entails.
>
> While it may be different for third party RAID controllers, the
> manual for
> the RAID controller on the ABIT KG7-RAID motherboard says that you
> need 4
> drives to use RAID 0+1 and that the second pair duplicate the first
> pair.
> This appears to contradict your point concerning "You "pay" the
> equivalent
> of one drive i.e.. - in this case - 100 GB for the security of your
> data,
> but you end up with a 300 GB drive array." If I ma reading the
> manual
> correctly, at least on the ABIT RAID, you would have 200GB of
> original data
> storage and 200GB duplicate mirror backup protection under the RAID
> 0+1
> setup - especially if you follow their advice of using same size,
> make, and
> model of hard drive in the array. Could you comment on this in a way
> so as
> to add some clarification for a novice to RAID arrays.
>
>
> -----Original Message-----
> From: owner-filmscanners@halftone.co.uk
> [mailto:owner-filmscanners@halftone.co.uk]On Behalf Of Preben
> Kristensen
> Sent: Sunday, November 11, 2001 5:35 AM
> To: filmscanners@halftone.co.uk
> Subject: Re: filmscanners: Best solution for HD and images
>
>
> IMO the best price/performance/data safety setup is IDE Raid 5. If
> you buy a
> Ide Raid 5 card (Adaptec makes a good one: 2400A, which sells for
> around 300
> US) you can then connect, say four IDE 100GB drives and get an array
> which
> is very fast AND fairly fault tolerant. You "pay" the equivalent of
> one
> drive ie. - in this case - 100 GB for the security of your data, but
> you end
> up with a 300 GB drive array and the ability to swap/hotswap a drive
> and
> rebuild the array should one of the drives fail.
>
> Also, by using UDMA/100 5400 instead of 7200 drives you get a
> slightly
> slover performance, but you gain by having much lower temperatures
> and much
> lower noise levels.
>
> Such a Raid 5 system would cost around 1300 US (depending where you
> buy) for
> 300 GB, but your data is much more secure than the simpler and
> cheaper Raid
> 0.
>
> Lastly, these stand alone Raid cards - unlike raid solutions on
> motherbords - have their own processors on board which takes over
> all the
> hard work, freeing up your system processor.
>
> Greetings Preben
>
>
> ----- Original Message -----
> From: "James Grove" <jpgrove@blueyonder.co.uk>
> To: <filmscanners@halftone.co.uk>
> Sent: Sunday, November 11, 2001 9:46 AM
> Subject: RE: filmscanners: Best solution for HD and images
>
>
> > I have just ordered a 60 Gig Maxtor ATA 100 drive (ATA 133 is also
> > available) I have done this because it is far cheaper than buying
> > another 36 gig drive to go on my U160 SCSI channel. I can get the
> Maxtor
> > drives for around 60 UK pounds, which means I could buy 4 of these
> IDE
> > drives for the same price as a Quantum U160 36gig drive!
> >
> > One thing to remember about Ide if you decide to give the drive a
> > beasting is to cool it with a slim cooler.
> >
> > --
> > James Grove
> > james@jamesgrove.co.uk
> > www.jamesgrove.co.uk
> > www.mountain-photos.co.uk
> > ICQ 99737573
> >
> > -----Original Message-----
> > From: owner-filmscanners@halftone.co.uk
> > [mailto:owner-filmscanners@halftone.co.uk] On Behalf Of Ezio c/o
> TIN
> > Sent: 10 November 2001 21:18
> > To: filmscanners@halftone.co.uk
> > Subject: Re: filmscanners: Best solution for HD and images
> >
> >
> > I would recommend to buy a U-160 SCSI ... from e-bay ... I have
> just
> > done this to integrate the other 3 U-160 I have and I have bought
> for
> > 102US $ a 18GB IBM 10000 rpm brand new under warranty. A 36GB
> 10000rpm
> > also IBM U-160 is rated for 170 US $ ...
> >
> > Sincerely.
> >
> > Ezio
> >
> > www.lucenti.com e-photography site
> >
> >
> > ----- Original Message -----
> > From: "Andrea de Polo" <andrea@alinari.it>
> > To: <filmscanners@halftone.co.uk>
> > Sent: Saturday, November 10, 2001 4:53 PM
> > Subject: filmscanners: Best solution for HD and images
> >
> >
> > > Hello,
> > >
> > > I have a CreoScitex scanner with attached a, Apple G4 Silver 733
> with
> > > OS
> > 9.2.1 and 1GB of ram; I noticed that the internal HD is a slow
> 5400rpm
> > UltraAta HD; question: since I work only with Photoshop and my
> images
> > are about 60mb in size and I just have to open and save them during
> the
> > day (we process about 200 images/day), I was wondering what is the
> best
> > and effective way to speed up my work: buy a scsi external HD
> 10.000rpm
> > (total cost about 650 UK pounds), OR buy an internal UltraAta 7200
> rpm
> > (total cost about 250 UK pounds) ???
> > >
> > > Again, we just have to open, retouch and than save our 40mb
> images,
> > > but
> > currently I am noticing that is taking a bit to access the HD.
> > >
> > > Thanks to give me your best solution for time/money issue. Andrea
> > > --
> > > ------------------------------------------------
> > > Fratelli Alinari Photo Archives and Museum
> > >
> > > The world's oldest picture library
> > > tel: +39-055-2395201
> > > gsm: +39-347-4883223
> > > fax: +39-055-2382857
> > > ------------------------------------------------
> > >
> >
> >
> >
>
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