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After 60 Years, Tape Reinserts Itself
Lucas123 writes "While magnetic tape is about as boring as technology gets, it's still the cheapest storage medium and among the fastest in sequential reads and writes. And, with the release of LTO-6 with 8TB cartridges around the corner and the relatively new open linear tape file system (LTFS) being embraced by movie and television markets, tape is taking on a new life. It may even climb out of the dusty archives that cheap disk has relegated it to. 'Over the last two years, disk drives have gotten bigger, they've gone from 1TB to 3TB, but they haven't gotten faster. They're more like tape. Meanwhile, tape is going the other direction, it's getting faster,' said Mark Lemmons, CTO of Thought Equity Motion, a cloud storage service for the motion picture industry."
Once again, Reel-To-Reel computers are no longer anachronistic in 60's Sci-Fi shows.
Sure, it reinserts itself, but when it's finished does it take itself out, flip it to the other side, and then reinsert itself again?
I have twenty terabyte backups NIGHTLY. I am required to keep certain tables (files by another name) for seven years but fortunately not all of it has to be online. I have over twenty terabytes I have to have backed up each night and a specific number of these backups available both on and off site. I have copies of quarterly and yearly complete backups I have too keep.
Show me a disk solution that is even remotely affordable. Cheap disk, maybe if you don't have any real amount of data and are not legally bound to keep it.
* Winners compare their achievements to their goals, losers compare theirs to that of others.
I'd love to use tape again, but with 1.5/3.0TB drives selling in the $1,500 range it still doesn't make sense, not when I can buy a dozen 2TB hard drives for the price of one 1.5/3.0TB tape drive
Right, and if all you need is a few dozen drives, it's probably not worth it. Let's talk when you need to backup 12 TB every night and you can only recycle the tapes yearly. Two drives and 1800 tapes is cheaper than 1800 drives, and until convinced otherwise I believe the tapes will take the time in storage with a better chance of coming back to life.
Tape isn't for days of storage, it's for archival.
The problem is that a 1.5 TB tape costs $50 and were it not for the flooding in Thailand, a 3 TB hard drive would cost under $80 like they were last year, which means that you never break even with tape cost-wise no matter the volume.
And then there's the added inconvenience. When lots of desktop computers come with a 3 TB hard drive and your tapes only hold 1.5 TB apiece, that means that even home machines are split across multiple tapes. This means the $1500 bare tape drive isn't enough to back up even a home computer. You'll need that $5,000 tape library instead.
Also, I wish people would quit calling LTO-6 an 8 TB drive. It uses only a 3.2 TB tape, which is too small to even back up hard drives that were shipping three months ago (4 TB) without compression. So the product that they haven't even started shipping is already hopelessly out of date, just has been the case for every consecutive generation of tape drive for at least the last ten years. Even more amusingly, the tape industry keeps creeping up in their estimates of compression. It used to be that their best-case capacity estimates assumed 2x compression. Now it's 2.5x. They're trying to look like they still matter, when in reality, they're falling further and further behind the hard drive industry. If it provided 8 TB uncompressed, I would consider buying one (assuming the tape price were under a hundred bucks a tape), but tape drives will really only be interesting to me if they actually get out ahead of peak hard drive capacity by enough of a margin that the tape drive will still be able to back up an entire machine in less than three or four tapes after a few years. Otherwise, they will never make sense unless you're backing up terabytes per day.
It's a shame, too. I really liked owning a tape drive back in the late 1990s. The big difference is that my computer at the time was five years old and had a small hard drive, so I was able to buy a used tape drive for under a hundred bucks that would back it up onto a single tape that cost me ten or twelve dollars. The difference between that and a $1,500 drive with $100+ tapes is not small.
For big, institutional setups where you're backing up terabytes per day, tape might still make sense, but only because hard drive prices are temporarily high and because storage space has a nonzero cost. For folks with more realistic daily data deltas, they're way too expensive, way too small, and for all practical purposes, completely irrelevant already. It's going to take a lot more than being able to back up 3/4ths of the current top-of-the-line hard drive per tape before tape will make sense again.
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Right, and if all you need is a few dozen drives, it's probably not worth it. Let's talk when you need to backup 12 TB every night and you can only recycle the tapes yearly.
Realistically, I have had a larger home file server than the entire corporate NAS/SAN at my last few jobs. And not talkin' about four-person mom-n'-pop shops here.
And yet, they all insist on using tapes for backup. Drives me up a wall to see the inefficiency.
After two years at my previous job, I finally convinced the head of IT to cycle through a handful of hot-swappable eSATA HDDs instead - After we had an actual serious crash and found tape after tape after worthless tape of complete unrecoverable garbage (despite never hearing a peep about corruption from the backup system). It took less than a week before I got to play the hero when we could recover a VP's "oops"ed spreadsheet in under a minute (as opposed to a day's work just to realize we had no viable backups).
Tapes may count as a "safe" industry standard, but anyone using them really needs to reevaluate their business needs. They definitely do have their strong points at the very highest end, but the standard "weekly backup with a nightly incremental" ain't one of them.
Full disclosure: I work as a professional backup/recovery sysadmin. I have been working with tape for over seven years. It's not dead; far from it. Now, if you want to argue that there are areas where it used to make sense, but doesn't any more, I'd completely agree with you. But consider one usage case as an example of how tape is still incredibly useful - this is taken from a company I did work for a couple of years ago.
You have multiple petabytes of data. At any given point in time, you need to be able to access a specific subset of that data. You can predict, ahead of time, 95+% of the data that you will need in (say) a week's time. The rest, you don't need to be able to access quickly, but you have to retain it, because it's expensive (if not impossible) to reproduce. Once you're done with the data, you might not need it again for a year or more, or you might need it again in a few days (possibly a few hours.)
So: you could have a very large disk array to store all that data. The hard drives are relatively cheap individually, but the support infrastructure to merge them into large arrays is expensive. The cost to keep them all online (electricity, cooling) is high. The probability of failure is relatively low, but the rebuild time if it happens can be high, depending on how things are structured. The marginal cost of adding more storage is relatively high: you have to get a new array, new disks, new fibre connections, hook it all up, hope you have enough power, ...
Or you could have a large tape library, with multiple high-capacity drives (LTO4 in the case of the customer I'm thinking of), and thousands (yes, I'm serious) of cartridges. The data is written to the tapes; ideally duplicated (this customer didn't do that; I reckon they were stupid); and then deleted from the hard disk staging area (only a couple of TB in size.) When a given piece of data is needed, it's read off the tapes in advance, written to disk, and then accessed from the disk. Once it's no longer needed, it's simply deleted off the disk (since it's already on the tape.) Marginal cost of adding more storage: how much does a single tape cartridge cost? (maybe a storage frame if the library's full; they aren't exactly cheap, but they do hold over 1300 cartridges each: over a petabyte in potential capacity with no extra electrical requirements [LTO4; double that for LTO5], bang, done.) Electrical and cooling requirements: significantly lower; you only have to worry about a couple of TB of disk space, and a few tape drives, plus the tape robot. Rebuild time: just copy it off the redundant copy if the tape's bad.
Is this sort of usage typical? No, not really. But it's certainly not abnormal, and this is the sort of case where tape whomps all over disk when you sit down and work through all the numbers (look at it generally, rather than thinking just about the specifics outlined; they illustrate the point, and aren't the entire point themselves.) Tape's also useful if you need to move large quantities of data offsite (backups, anybody?) and can't afford, or don't want, high capacity fibre out of your data centre to another remote location.
I agree that "capacity after compression" is pure marketing; I do my figuring based upon native capacity (800 GB for LTO4; 1.5 TB for LTO5; 5 TB for T10000C; 3.2 TB - we hope - for LTO6). But to say that tape is "way too expensive, way too small, and ... completely irrelevant" is to misunderstand the strengths and uses of tape. Like I said: look at all the numbers, not just the purchase cost per raw TB, and pick whatever's right for the application in question.
Oh, and the use case I outlined above? It's for a pay TV network. TV shows, movies, sporting events, concerts, documentaries. All purchased legally, but impossible to reproduce (sporting events), or expensive to re-procure (TV shows, movies) if they're lost. Think about it.