Archival properties of zip files

[DeeJay]

I'm totally rethinking my long term archivals at the moment so here is another question for anyone who may be able to answer. I wondered how archival zip files are?

They obviously save space so are useful for archiving, but will they unzip ok in years to come?

Thanks,

[feppe]

Zip is more common than any RAW format, (de)compression algorithms are publically available and can be done with free open source tools unlike all common RAWs, so zipped files are more likely to be able to read far into the future.

The main reason why I don't zip my backups is that it creates an additional step which can potentially break things. KISS and all that. Also, if you have physical damage on your backup, recovering zip files can be more difficult (read:costly) than uncompressed individual files.

[PierreVandevenne]

Yes, no doubt about that particular point.

You'd have to assume a world where all current OSes have disappeared, Google isn't remembered, no paper traces exists and high school students have been changed into retards and much worse for the knowlegde/means to unpack zip files to disappear from the face of the earth.

BTW, the underlying compression algorithms are used in zillions of other things, software and hardware, transparently.  

Note that

- this support doesn't solve the issue of the format of the files stored into zip files. Assuming a manufacturer with a closed raw file format goes out of business, you worry if for that particular file format support, not for the zip container.

- compression isn't going to gain much on already compressed picture storage formats.

And anyway, if there is a need, no file format is going to end up in a dead end nowadays. It will always be possible to reverse engineer a file format. There was a lot of talks about these issues in the early 80s and the feeling was that the ability to handle some type of documents would be compromised in the future. The general perception was something like "The Apple II is top of the line now. It will not always be. It will be forgotten and some data collected on those computers could become lost forever". Today, if I really had not other means to recover old lab data (that isn't the case), I could simply launch an Apple II emulator on a cheap smart phone.

That doesn't mean that there aren't issues, but they are more at the physical format level (what do I do with that obscure backup tape? Do I still have a machine to read that? what do I do with my rotten CDs? what do I do with that crashed hard drive?) than at the interpretation of data level.