Offsite backup strategy failed - now what?

[Tesselator]

Originally Posted by nigelbb

Magnetic tape does not suffer damage from cosmic rays. That idea is utter tosh. Cosmic rays are charged particles they don't interfere with magnetic particles on tapes. Computer memory may rarely be altered by cosmic rays which is one reason why servers use ECC memory. In the old days of reel to reel tape it was good practice every year or 2 that the tape was de-spooled & re-spooled to prevent data 'burning through' but better design of more recent cartridge tapes means this is no longer necessary.

That's funny. If you studied a little you would know there is just about nothing on this planet that isn't damaged by cosmic rays and BG radiation - including you and I, but also hardened steel, glass, ceramics, chrome, plastics of all kinds. Really, everything!

So it's kinda silly to suggest that magnetic tapes are unaffected. LOL Now consider their construction... Spooled in a tight spiral. When a ray hits it, it doesn't just damage one area on a flat surface like disks are formed as... no, it may go through hundreds of layers and cause a whole bunch of information loss with just one strike.

You can do a search and find out how many millions of ray events are striking the Earth every second if you'd like. From there it's only a few simple equations to determine the chance over time that something the size of one of those tape spools gets hit - and how many times per period, etc.

Remember the Ultrium 5 and 6 tapes now have a data density 15,140+ bits/mm and the 1980's tapes you're referring to were 800 or 1600 CPI. That's about 566 bits/mm in the later case - half that for the 800's. The industry stopped updating the standards of those systems at about 2200 bits/mm and those were 9-track tapes with a parity track. You can also research the relationship between data density and cosmic ray damage quite easily - the studies are numerous and prevailing.

I know you want to defend tape but we have to be honest about things too.

[nigelbb]

I wasn't suggesting that magnetic tape doesn't get hit by cosmic rays just refuting the nonsense that

Tape is particularly vulnerable to background radiation and cosmic rays.

It's not. Data tapes have an archival life of at least 30 years without any special storage requirements other than normal humidity & temperature.

[Tesselator]

Originally Posted by nigelbb

I wasn't suggesting that magnetic tape doesn't get hit by cosmic rays just refuting the nonsense that It's not. Data tapes have an archival life of at least 30 years without any special storage requirements other than normal humidity & temperature.

Well, I just explained why in fact it actually is so in my previous post. There's not a thinking scientist on the planet who would argue the point. It's of course up to you weather to buy into the distributed marketing sheets or trust common sense and science. <shrug>

My reaction:

30 Years: ROFLMAO! (and that's the 1st time I've ever used that acronym!)
10 Years: Unlikely!
5 Years: If you're lucky - sure.
3 Years: Probably, yes.

[nigelbb]

Care to provide some evidence or even a reference to support the statement that "Tape is particularly vulnerable to background radiation and cosmic rays"?

[d-m-a-x]

Originally Posted by nigelbb

Care to provide some evidence or even a reference to support the statement that "Tape is particularly vulnerable to background radiation and cosmic rays"?

Go to a thrift store and buy a 30 year old Indiana Jones Vhs tape and see how it looks compared to a tape from 2002 - the tech is the same, the difference is staggering

[brentsg]

Originally Posted by d-m-a-x

Go to a thrift store and buy a 30 year old Indiana Jones Vhs tape and see how it looks compared to a tape from 2002 - the tech is the same, the difference is staggering

That VHS tape from 25+ years ago was quite likely used and abused if it wasn't a rental in a previous life. I wouldn't call that a proper comparison.

[d-m-a-x]

Originally Posted by brentsg

That VHS tape from 25+ years ago was quite likely used and abused if it wasn't a rental in a previous life. I wouldn't call that a proper comparison.

i see the same thing in old unexposed motion picture film that has been sitting for a long time. The upper part of the frame is partially exposed and has extra noise.

probably why the edges of the optical discs go first when stored verticaly

[nigelbb]

Originally Posted by nigelbb

Care to provide some evidence or even a reference to support the statement that "Tape is particularly vulnerable to background radiation and cosmic rays"?

Originally Posted by d-m-a-x

Go to a thrift store and buy a 30 year old Indiana Jones Vhs tape and see how it looks compared to a tape from 2002 - the tech is the same, the difference is staggering

That is no proof of damage by cosmic rays or indeed proof of anything else. I had a good look around & can find not a single reference to tapes being damaged by background radiation and cosmic rays even less that tape is particularly vulnerable. You statement is simply not true.

[Tesselator]

Yeah, LOL we've come to a really strange place here:

It's not on the internet so it's not true!

I couldn't find a link so it doesn't exist!

Did everyone laugh their butts off when they read that or just me?

[nigelbb]

Just you I am afraid as given the impossibility of proving a negative the onus is on those who claim that "Tape is particularly vulnerable to background radiation and cosmic rays" to either offer some proof for this statement or S.T.F.U..

Tape & magneto-optical discs are the archival media of choice for computer data because the integrity can be guaranteed for decades. This is of course not very impressive compared to other storage media that can store data for hundreds of years e.g. paper.