But Curtis, a disk drive by itself isn't very useful either - you'll need to
a controller or two.

And don't forget to factor in the price of the de-duplication appliances or
software.  Those suckers are *NOT* cheap.  An appliance to support 1TB of
compressed data lists out at about $20K.  Unless you get a *lot* of
de-duplication - and not everybody does - that appliance is going to get
killed on price compared to not de-duping it.

It took me only 30 minutes with a de-dupe vendor last week to eliminate
their product from consideration in our environment.

        .../Ed

--
Ed Wilts, RHCE, BCFP, BCSD
Mounds View, MN, USA
mailto:ewilts AT ewilts DOT org


> -----Original Message-----
> From: veritas-bu-bounces AT mailman.eng.auburn DOT edu [mailto:veritas-bu-
> bounces AT mailman.eng.auburn DOT edu] On Behalf Of Curtis Preston
> Sent: Friday, September 21, 2007 12:10 PM
> To: Justin Piszcz; Jeff Lightner
> Cc: veritas-bu AT mailman.eng.auburn DOT edu
> Subject: Re: [Veritas-bu] Tapeless backup environments?
> 
> First, you can't compare the cost of disk and tape directly like that.
> You have to include the drives and robots.  A drive by itself is
> useful;
> a tape by itself is not.
> 
> Setting that aside, if I put that disk in a system that's doing 20:1
> de-duplication, my cost is now 1.65c/GB vs your 3-9c/GB.
> 
> ---
> W. Curtis Preston
> Backup Blog @ www.backupcentral.com
> VP Data Protection, GlassHouse Technologies
> 
> -----Original Message-----
> From: veritas-bu-bounces AT mailman.eng.auburn DOT edu
> [mailto:veritas-bu-bounces AT mailman.eng.auburn DOT edu] On Behalf Of Justin
> Piszcz
> Sent: Friday, September 21, 2007 7:36 AM
> To: Jeff Lightner
> Cc: veritas-bu AT mailman.eng.auburn DOT edu
> Subject: Re: [Veritas-bu] Tapeless backup environments?
> 
> 
> I believe disks are 33c/gigabyte and tapes are 3-9cents/gigabyte or
> even
> 
> cheaper, I do not remember the exact figures, but someone I know has
> done
> a cost analysis and tapes were by far cheaper.  Also something that
> nobody
> calculates is the cost of power to keep disks spinning.
> 
> Justin.
> 
> On Fri, 21 Sep 2007, Jeff Lightner wrote:
> 
> > Disk is not cheaper?  You've done a cost analysis?
> >
> > Not saying you're wrong and I haven't done an analysis but I'd be
> > surprised if disks didn't actually work out to be cheaper over time:
> >
> > 1) Tapes age/break - We buy on average several hundred tapes a year -
> > support on a disk array for failing disks may or may not be more
> > expensive.
> >
> > 2) Transport/storage - We have to pay for offsite storage and
> transfer
> -
> > it seems just putting an array in offsite facility would eliminate
> the
> > need for transportation (in trucks) cost.  Of course there would be
> cost
> > in the data transfer disk to disk but since everyone seems to have
> > connectivity over the internet it might be possible to do this using
> a
> > B2B link rather than via dedicated circuits.
> >
> > 3) Labor cost in dealing with mechanical failures of robots.   This
> one
> > is hidden in salary but every time I have to work on a robot it means
> I
> > can't be working on something else.   While disk drives fail it
> doesn't
> > seem to happen nearly as often as having to fish a tape out of a
> drive
> > or the tape drive itself having failed.
> >
> >
> > -----Original Message-----
> > From: Justin Piszcz [mailto:jpiszcz AT lucidpixels DOT com]
> > Sent: Friday, September 21, 2007 10:08 AM
> > To: Jeff Lightner
> > Cc: veritas-bu AT mailman.eng.auburn DOT edu
> > Subject: Re: [Veritas-bu] Tapeless backup environments?
> >
> >
> >
> > On Fri, 21 Sep 2007, Jeff Lightner wrote:
> >
> >> Yesterday our director said that he doesn't intend to ever upgrade
> >> existing STK L700 because eventually we'll go tapeless as that is
> what
> >> the industry is doing.   The idea being we'd have our disk backup
> >> devices here (e.g. Data Domain) and transfer to offsite storage to
> >> another disk device so as to eliminate the need for ever
> transporting
> >> tapes.
> >>
> >> It made me wonder if anyone was actually doing the above already or
> > was
> >> planning to do so?
> >>
> >
> > That seems to be the way people are 'thinking' but the bottom line is
> > disk
> > still is not cheaper than LTO-3 tape and there are a lot of
> advantages
> > to
> > tape; however, convicing management of this is an uphill battle.
> >
> > Justin.

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