Also, we use raw storage in the context of _individual_ incompressible backup sets, not backup data at scale, because very few places backup a high ratio of incompressible data overall.

I'm not convinced that's true. At home, my NAS uses compression, so the raw capacity of the tapes is likely the relevant one, unless the tape somehow manages to recompress lz4-compressed blocks and gain a benefit (not entirely impossible, as lz4 is optimised for speed, but pretty unlikely). At work, the NetApp filer that the tape backups run from also uses compresses and deduplicates online, so not much redundancy there either.

My impression is that a growing percentage of data these days cannot be compressed further:

• Media (pictures, movies, etc.) makes up a growing percentage of data, and is already so compressed that it won't compress further.
• Source code stored in a git archive uses LZW, IIRC, so unless you're compressing a checked-out copy, compression won't buy you much, if anything.
• More and more document files are compressed—Pages files are ZIP archives, EPUB books are ZIP archives, and so on.

I shoot RAW, so 80 GB sounds hopelessly tiny to me. The portion of my photo library that I carry around on my laptop, by itself, would take more than 6 of those tapes to back up once. The entire library would probably be around 10–12, but I don't feel like digging out the external drive just to get a more accurate estimate. :-)

And the DAT-160 tape prices, unlike the drive prices, haven't come down. At $312.50 per terabyte, the tapes cost 10x what a hard drive costs and 5x what laptop drives cost. So you could back up your data 5 times on hard drives for the same cost as backing it up once on tape. And the laptop hard drive would hold as much data as 25 of those tapes, so it will take up an order of magnitude less space to use hard drives as well.

Well, it allows you to recover data in the event of a hardware failure specifically on one of the hard drives, nowhere else, in such a way that doesn't cause data corruption first. In much the same way that if you have a redundant power supply, it will protect you against the specific event of hardware failure where one of your power supplies fails without there being a problem with your power source or damage to any of the other internal components.

That is to say, it's hardware redundancy. Nothing more. Of the events that lead to data loss or power failure, hardware redundancy does protect you against the case where the problem is limited to hardware failure of one of the redundant parts, and everything else works properly. A "backup" however should be a more generalized strategy for protecting against a total loss of the service, i.e. power goes out or data is lost.

This isn't a competition. I'm not saying, "Screw RAID! It's a terrible backup." It's just not a backup. I'm not going to fight with you over this. Go ahead and use RAID as a backup. Maybe you'll be lucky and you'll never need to learn your lesson.

You might do better to ask why yours seems to pretend it couldn't happen.

AC, please. Anybody with five minutes--and the sense that God granted a goose--can see you're attempting to rewrite history in a pretty major fashion.

China would like to speak to you about paper, gunpowder, the printing press, the magnetic compass, and the fork. Amongst other things.

You've evidently got me mixed up with someone else who said things that I did not. Thanks for playing, though.

Some of us do this thing known as "work" with our browsers. Making radical changes in my UI with neither prior warning nor a built-in way to revert to the previous layout is not something which I find to be particularly workflow-friendly.

There. Managed to say it without foaming at the mouth, this time. ;)

I used to use tape for backup. The reason I stopped was that it stopped being cost effective. There was a time when you could buy one-generation-before-current tape drives, back your entire hard drive up more than once on a tape, and if you bought more than a dozen tapes, you spent less money overall than buying hard drives for those backups.

For about the last decade, tape has lagged so far behind hard drives that this hasn't been the case. You couldn't back up a high-capacity hard drive on last-generation tape. In fact, the current-generation LTO-6 only holds 2.5 TB uncompressed, so in the worst case, you can back up any hard drive built before 2010 (when the first 3 TB hard drives came out). And that tape technology didn't come out until 2012.

And you'll spend almost $3k on the drive, plus $45 per tape, or $18 per terabyte. Hard drives are currently running at $30 per TB. So ignoring differences in risk between a hard drive on a shelf and a tape, the break-even point is at a whopping 250 TB—almost an order of magnitude more than is reasonable for most businesses, much less consumers. Unless you're doing data warehousing, this break-even point is simply too high to be practical. Yet this is the smallest tape drive that is practical for any serious use, because one-generation-old drives (LTO-5) take 2–3 tapes just to back up an average desktop hard drive once, and the break-even point at $33 for 1.5 TB is still over 200 TB. That's just nuts. If you're willing to use ten tapes per drive, you could use LTO-3, but at $30 per terabyte plus the cost of the drive, you never break even at all.

To make a long story short, tape died the moment they stopped building tape drives targeted at normal consumers. As with all specialized products that are too expensive for normal people to afford, over time, cheaper, more consumer-friendly technologies begin to take advantage of their dramatically higher sales volume to drive R&D that allows them to eventually become "good enough" to be used in place of those niche "professional" products for their least demanding customers, thus causing the market to get smaller and smaller. As demand drops, prices then increase, causing even more potential customers to start looking for alternatives, until eventually the death spiral reaches its ultimate and inevitable end: a market that has dried up completely. This same scenario has played out in industry after industry over the years, and anybody who didn't see the writing on the wall more than a decade back must not have been paying attention.

Want me to stop saying tape is dead? Prove me wrong. Ship a consumer-grade LTO-6 drive for $300. Make tape a feasible backup medium for consumers and small businesses. Short of such a drastic step, tape is pretty much doomed to fade into obsolescence. At this point, I'm firmly convinced that the only real question anyone should be asking is how best to handle backups and archiving in a post-tape world; without a giant cash infusion and a radical change in the leadership of companies that build these products, it's not a matter of whether, but rather a matter of when.

Sorry, no, in IT terms that's not a backup. It's a backup when it's an independent system with a history. Calling a RAID1 a backup to protect against data loss is similar to calling a redundant power supply a backup to protect against power failure. It's kind-of-almost-right in a limited sense, but it misunderstands the problem. It's just hardware redundancy, not a backup.

The problem with that is that nuclear power contaminates the turbines. Badly. You're heating the water that spins those turbines by passing it over a nuclear pile. You're not realistically going to be able to use them with any other heat source after that. But I agree about prebuilt, small-scale reactors being a better solution. In addition to having fewer quality control problems (for example, less risk of "oops, the pipes are wearing out dramatically faster than expected" situations like we saw with San Onofre), a smaller plant would also presumably be easier to deal with in the event of a serious failure.

You're both right. RAID can decrease the chances of data loss due to some kinds of problems, but ultimately it shouldn't be considered a reliable protection against data loss. A RAID can be lost or corrupted, or someone can overwrite or delete a file. If you want to assess the risk to your data and talk about the set of data that is protected against loss, you should only consider your backed up data to be "protected". The protection that RAID offers is too weak to be considered to be significant protection.

Therefore, the fundamental purpose of a RAID is to prevent the downtime due to failure of an individual hard drive. If you did not have RAID, then your data volume would stop running, and you'd have to be offline while you repair the device and restore from backups, so that's what you're successfully preventing. All the data that has been backed up (assuming your backup is good) should be safe, and any data that has not backed up is not safe, regardless of whether you have a RAID.

RAID is redundancy, not backup.

What's wrong with you people. We are waiting already for 5+ MORE THAN FIVE fucking years. Still hasn't happened.

1TB HDD - 60-80€, 1TB SSD - >350€.

The problem is that once PC is turned on, there is not much use for the SSD speed. It's not like I'm moving terabytes of data around everyday. And even if I have to, I do not have to wait for it: I simply leave it overnight.

Another problem is that (some) SSD have the nasty habit, once failed, to deny you access to the data at all. I hoped that at least those jackasses would straighten out the SMART support and finally standardize the monitoring parameters. But few moronic manufacturers even proclaimed that their drives are so good that they don't need no stinking SMART support...

All in all, SSDs are developing too fast. And have pretty bad history of firmware bugs. And literally all manufacturers, instead of strengthening their stance of data safety, all like one doubled down on the "oh but look how fast it is!"

P.S. And TRIM support is still in shambles. After all the years, some drives still require a proprietary application/driver installed.

lol, what the hell do you think refusing to change seats is?