At what scale does tape begin to make financial sense?
- Having the data be offline, ie, not available to an attacker which somehow managed to take control over your network
- Having the data be in a physical format which can be easily put in a safe or in the back of a car when there is a risk of flood or fire
- Having data on a media that won't regrade over a period of say, 10-30 years. Hard-drives tend to fail
So, yeah, spinning rust might rust.
Manual labour.
There are tape libraries with robots that can take a tape out of a slot, put it in a drive, and then put it back automatically without humans needing to do anything. If you want to move the tapes offsite, there is some manual work to move the tapes from the import/export slot to a container.
A large library like the StorageTek SL8500 can have up to 640 drives, 100'000 tape storage slots, and 2'880 import/export slots.
Big cloud providers have disk replacement robots, so it's not unfeasible for robots to perform the "unplug and store the HDD somewhere".
But another advantage tape has is durability.
[citation needed]
I have no idea if anything like this is actually in use, I have my doubts. Also, a system like this probably isn't terribly useful, a Cartesian gantry robot would be much faster and way more robust than an articulated arm strapped to a mobile robot platform.
Wow the scale is just immense, that's pretty cool!
Both of these issues can be largely mitigated by simply plugging the HDDs in every year or so and re-writing the data (maybe run badblocks while you're at it to ensure the drive is still in good health), but, as throw0101a mentioned, this takes time and effort.
[0]: https://serverfault.com/a/51893
[1]: https://www.partitionwizard.com/clone-disk/do-hard-drives-go...
How long a given SSD will last before losing data depends on the chips it is built with. I remember reading that Sandisk rates their flash storage as being able to survive a year without power (though I read that years ago and cannot find a source for it now), though [0] says 2-5 years, so technology has likely advanced since I last read about this. Either way, you should probably try and power up your SSDs at least once a year to keep the cells charged. This is less work than to keep an HDD healthy for cold storage, but it certainly isn't "set and forget" like tapes or optical disks.
Edit: I remember pulling my first SSD, a 60 GB Intel 330, from an old laptop and, despite having not been powered on for 3 years, it still booted. But that was MLC/DLC [1], which only has 4 voltage states, and I only saw that it booted, not that all my old data was intact.
[0]: https://www.easeus.com/resource/does-ssd-need-power.html
[1]: https://www.intel.com/content/dam/www/public/us/en/documents...
And if you replace dead disks every month or two, a non-networked server can probably manage more reliability over 10-30 years.
(The three major tiers are A: I accidentally deleted a file or directory yesterday, so I need to get a copy from snapshots; B: the machine I was working on exploded, so I need to rebuild it and repopulate it with my data; C: archive for some need in the far future)
Suppose you have large quantities of data that you need to preserve for legal reasons -- it's always legal reasons, unless you are in academia or similar -- but you will not be accessing much. That's when you use tapes.
For most other purposes, you want a snapshotting filesystem or an offsite filesystem made from those snapshots.
If you just want to store lots of data in a single place I think MAID still beats the tape at any scale (especially if you want automated retrieval)
It's discouraging that it's so complicated which made me back out of the purchase a few times, but it was well worth it.
The tape itself is quite cheap (LTO-9 is 18TB for $100), but the drives are expensive ($5000+ for an LTO-9 drive), so you need quite a bit of volume to make it worth it.
You can get an earlier breakeven point by buying used equipment for older generations. But no matter what you do, at small scale hard drives will be cheaper (and can be put on a shelf or in a safe too)
Essential when data is created faster than the locally available internet bandwidth which in media industries is quite often.
For larger amounts of data, the money savings vs. HDDs increase quickly.
The break-even point vs. HDDs is lower for long-term archiving than for short-term backups, because the lifetime of tapes is much longer (it is limited not by the degradation of the tapes but only by the risk that compatible tape drives might become hard to obtain), so you need multiple HDDs to store data for the lifetime of a single tape.
Right now you can get 18TB drives for $290 so you can get 306TB for $4,930
Have any data to back your claim?
So perhaps not 100% immune, but partial immunity to bit-rot is a pretty important part of the LTO spec.
I suppose that's anecdote. :) But it's what I've got.
Search for "year" in the specification of HPE's Ultrium LTO media:
* https://www.hpe.com/psnow/doc/c04154430
Or IBM's white paper: