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Comment by robjan | Hacker News Reader

Another crucial importance is bytes per square centimetre. When archiving something, there's no point in archiving hundreds of storage controllers with it especially if you need to store them in a safe (which you probably should). MicroSD cards may beat tape but they are a lot slower and harder to label.

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Which one wins on long term storage durability, shock proof, and water damage?

https://en.wikipedia.org/wiki/M-DISC

LTO doesn't suffer from those things. Shock can destroy the case and dislodge the leader pin of an LTO cartridge but AFAIK it can't damage the data on the tape. Water is bad for the transport but as long as you dry your tapes out they should still work. The operating specs for LTO are crazy, you can read and write them under all practical atmospheric conditions.

Smoke haze will cause all kinds of trouble for tape drives though.

So don't run the backups when the DC is on fire, got it.

As will very dry conditions. The IceCube neutrino telescope at South Pole used LTO-3 tapes to store data until they switched to only hard drives around 5 years ago. At that point, the newer tape drives had been tried (IIRC LTO-5 was the industry standard by then) but they never seemed to work, presumably because the humidity on station is incredibly low. It was considered more reasonable to keep the old LTO-3 equipment in use, versus building a humidor for the tapes and drives.

Mr. Robot was a liar!

LTO turns out to be garbage on the key measure of "can I read my backups a little while down the road", because you'd be surprised how quickly a new LTO drive can't read old tapes.

It's unpleasant having to buy old drives to keep with your tape archives because you won't otherwise be able to read them any more.

Can't you just keep the old drives you wrote the old tapes with?

Until they break. Then you can't get a new one.

Source: have done this at scale, have spent time scouring the second-hand market to cobble together early-generation LTO drives.

Always buy two I guess. That messes with the affordability calculus though.

You should have at least two to have critical redundancy. Not to mention making backup testing easier.

Okay, so by 'a little while' you mean a pretty significant amount of time. If you plan up front to migrate to new tapes every two generations (shrinking your collection 4x in the process!) then you'll never need a particularly old machine.

Yeah, well true but mechanisms degrade and each generation is a pretty long as electronics go. The two generations ago reading should be an indication that you need to retake the old data. Getting old working drives is a pain, and the rental prices aren't cheap because you often need an expansion card to interface with the older drives.

I don’t know why this is being downvoted, because it’s absolutely true. Any data you want to read years down the road should be retaped to newer media generations. Don’t rely on the promise that you can read tapes two generations back—test it yourself, if it’s important.

I had a room full of servers, many with 16-36 disks per server and had an AC failure. Things turned off as planned, but it hit 115F for a bit. None of the disks died, majority of the tapes did.

That sounds unusual. Tape shouldn't degrade that easily. 115F is 46C, which is hot for a human and not a good temperature for long-term storage, but not anywhere near immediately hazardous to the media. Was it LTO or some other type of tape?

LTO, the archival temp is REALLY narrow, only 61-77F. Just google "lto storage temperature" and google will pop up a card based on the IBM data.

That is the range of temperatures if you are going to be storing the tape for over 6 months.

Yes, note the operational temperature is below 115F as well.

That's if you are actively trying to do backup.

True, I don't remember if the backup software was running. However we lost tapes in the cartridge in the drive (7 tapes I think) and also tapes in other cartridges (banks of 7).

I think we had 4 cartridges of 7, then upgraded to a newer robot that had 8 cartridges of 11.

At the time I was pretty shocked, and asked around and apparently it wasn't a particularly unusual event. Fortunately we always kept a cartridge rotated out to a different room.

Also keep in mind the monitoring for the room hit 115F, so the temp inside the tape drive/robot might have been over 115F.

Similar with the drives, but the drives were fine.

That is really odd. LTO shouldn't do that. I would actually suspect the actual drive, but you probably got a replacement drive to check. That is well outside my experience. If I remember correctly they should be good to 120F for a little while.

Not sure if the tapes were permanently damaged or just had lost data. We ended up switching to a 16 disk server running backuppc. Not nearly the same capacity, but incrementals, deduplication, and compression made up the difference.

Also sadly the great price/performance brand with great service (overland) got bought up by the radically more expensive larger company and all the prices doubled 8-(.

Tape vs SD cards? Tape.

NAND flash can leak charge over time if not powered on which makes it unsuitable as an archival medium. Depending on P/E cycles each cell has undergone and the drive type (SLC/MLC/TLC/QLC) it can be from 3 months to 10 years.

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