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:[EMAIL PROTECTED] > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:veritas-bu- > [EMAIL PROTECTED] On Behalf Of Curtis Preston > Sent: Friday, September 21, 2007 12:10 PM > To: Justin Piszcz; Jeff Lightner > Cc: veritas-bu@mailman.eng.auburn.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: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Justin > Piszcz > Sent: Friday, September 21, 2007 7:36 AM > To: Jeff Lightner > Cc: veritas-bu@mailman.eng.auburn.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:[EMAIL PROTECTED] > > Sent: Friday, September 21, 2007 10:08 AM > > To: Jeff Lightner > > Cc: veritas-bu@mailman.eng.auburn.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. _______________________________________________ Veritas-bu maillist - Veritas-bu@mailman.eng.auburn.edu http://mailman.eng.auburn.edu/mailman/listinfo/veritas-bu