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Richard, I did a quick calculation based on what I have in the vault today and came up with some interesting numbers about the direction of data storage rates. Umatic 500 * 2 * 0.35GB=350GB (1981-1996) DAT 600 * 2 * 0.65GB=780GB (1988-2000) CD-R 900 * 0.75GB=675GB (1992-2010) 3324 200 * 12 * 0.75GB=1800GB (1988-2000) DTRS 800 * 8 * 1GB=6400GB (1997-2006) Hard Drives 600 * 1500=900000GB (0.9PB) (2001-Present) (This is a guesstimate. In the beginning there are some 100 and 500GB drives, but we have been burning though about 100 3tb drives a year for the last 3 years and it is only getting larger) At LTO7 prices of $48/TB for redundant copies plus $6000 for a pair of LTO7 drives, is virtually identical to a pair of 12 drive storage servers with spinning discs at $52/TB 10 drive RAID6 with 2 hot spares. The bigger difference here is the cost of electricity. A pair of servers running 24/7/365 is about $900/year. (3741kWH * $0.12=$445/yr each) So by my calculation, up to around 50 TB it makes sense to have online spinning storage, beyond that offline tape makes more sense. All the best, -mark On Thu, Jan 28, 2016 at 10:54 AM, Richard L. Hess <[log in to unmask]> wrote: > I concur with Corey here--I responded to Tom's new thread at greater > length, but tape was much more economical than spinning disks a decade ago, > and both have scaled upwards, moving the crossover point. > > I'm now at the 10 TB level for dual RAID-6 local storage with an > additional 5 TB of single RAID-6 local storage. > > A funny story about Sony marketing. In the late 1990s they showed a robot > that could hold 1000 TB of data on tape. They called it the Peta-File. The > next year, it was changed to Peta-Site. That was a decade and a half ago. > > My contention is that tape does not make sense for data storage until you > have a complete robotic system which includes tape cassette usage history > and automatic regeneration of tapes that have been used a number of times. > > While the number of "full file passes" on LTO tape has increased, it is > still relatively low and it's not useful for storage with many retrievals. > > Anything that requires manual storage module shuffling is doomed to not be > used as regularly as necessary--personal experience with my off-site backup > confirms this. > > Here is an example of where I think LTO tape (and I think LTO is now the > only viable data tape format) becomes useful: > http://www.quantum.com/products/tapelibraries/index.aspx > > This is a continuation of what I knew as ADIC storage, they were bought > out by Quantum in 2006. > > It is now a no brainer (in my opinion) to provide 10-20 TB in a single > RAID-6 enclosure. Eight 3 TB drives in a RAID-6 configuration provides for > about 15.8 TB of usable storage. Going to 4 TB drives would increase that > to about 21 TB. (Rememeber, drives are measured using 1000X multipliers > while files are measured using 1024X mulipliers. Linux properly calls those > numbers TiB and GiB (for binary).) > > 6 TB drives are commonly available now in RAID-tuned HDDs and for backup > use (not server use) the WD Red drives seem to be good. I am using this > line in 2, 3, and 4 TB (8, 8, 5 of each, respectively). So far, I had to > replace one 3 TB (which were new at the time) about 8,000 hours in...it was > an easy warranty replacement. > > My main server states. > > Used: 8.45 TB > Available: 7.41 TB > > Cheers, > > Richard > > > > On 1/27/2016 8:57 PM, Corey Bailey wrote: > >> Hi Tom, >> >> The answer is relatively simple: Money >> You and I think about storage in terms of a Terabyte or two. General >> Motors and corporations of that size have to think in terms of multiple >> Peta-bytes. LTO becomes the least expensive method. After the data is on >> the tape, verification and migration is done robotically. >> >> Those that are considering LTO need to know that the format (drives, >> etc.) is only backward compatible for two generations and LTO-7 is on >> the horizon. >> >> Cheers! >> >> Corey >> Corey Bailey Audio Engineering >> www.baileyzone.net >> >> On 1/27/2016 4:36 PM, Tom Fine wrote: >> >>> <SNIP> >>> Could someone explain why a somewhat antiquated magnetic tape-based >>> storage system is preferable to several copies across several hard >>> drives? I just can't see any sense in using tape systems anymore for >>> data security, but I'm not a computer-storage expert, just a guy who >>> stores a lot of data. >>> >>> -- Tom Fine >>> >>> ----- Original Message ----- From: "Hood, Mark" <[log in to unmask]> >>> To: <[log in to unmask]> >>> Sent: Wednesday, January 27, 2016 6:41 PM >>> Subject: Re: [ARSCLIST] LTO vs HDD >>> >>> >>> Hi Richard, >>> >>> Thanks as always for sharing your experience and insights on all of these >>> topics. >>> >>> Would you be comfortable sharing the make and model of the RAID-6 NAS >>> units you are using, and any comments about how well they have performed >>> to your expectations? >>> >>> Thanks, >>> Mark >>> >>> Mark Hood >>> Associate Professor of Music >>> Department of Recording Arts >>> IU Jacobs School of Music >>> >>> >>> >>> >>> On 1/27/16, 3:36 PM, "Association for Recorded Sound Discussion List on >>> behalf of Richard L. Hess" <[log in to unmask] on behalf of >>> [log in to unmask]> wrote: >>> >>> Hi, All, >>>> >>>> I saw this thread and was going to ignore it, but decided not to once I >>>> found out that RDX was HDD-in-an-otterbox merci, Henri, and thanks for >>>> the image, Lou. Otters are wonderful--see "Ring of Bright Water" (The >>>> book) and Point Lobos State Park. >>>> >>>> LTO was around while I was still doing broadcast consulting and, at the >>>> time (late 1990s, early 2000s). >>>> >>>> I struggled long and hard about how to store things and realized if I >>>> were going to become involved with LTO, I would need two drives (how >>>> else can you be even remotely certain that your tapes are readable once >>>> your single drive dies--I certainly saw that in the early days of PC >>>> tape backup. At that point, the cost becomes excessive. >>>> >>>> My philosophy now is: Any data I want to keep does not live solely on a >>>> PC. >>>> >>>> I have two in-house RAID-6 NAS units, one backing up the other; an ammo >>>> case of 2.5-inch HDDs off-site (2 TB 2.5-inch USB 3.0 drives are pretty >>>> economical these days and are USB-powered). >>>> >>>> One son has been migrated to the cloud where Dropbox backs up and >>>> mirrors his two on-site laptops. Here, I harvest all new files (but not >>>> updates to prevent pollution of existing files) and store them on my >>>> RAID-6 NAS units to protect against a Dropbox failure or hacking. The >>>> other son will do it soon, but the first one is potentially going far >>>> away to school next fall for his Masters (Wichita and Edmonton are on >>>> the list) so I wanted to get some closer-in history with the system. >>>> >>>> RAID-6 allows the failure of any two disks without losing data and the >>>> data does not have to be chopped up into 1 or 2 TB chunks as it does >>>> with HDDs. >>>> >>>> I do not keep CF/SD cards, I copy and verify the copy and then recycle >>>> them. >>>> >>>> Cheers, >>>> >>>> Richard >>>> >>>> -- >>>> Richard L. Hess email: [log in to unmask] >>>> Aurora, Ontario, Canada 647 479 2800 >>>> http://www.richardhess.com/tape/contact.htm >>>> Quality tape transfers -- even from hard-to-play tapes. >>>> >>> >>> >> -- > Richard L. Hess email: [log in to unmask] > Aurora, Ontario, Canada 647 479 2800 > http://www.richardhess.com/tape/contact.htm > Quality tape transfers -- even from hard-to-play tapes. >