: Archiving


csonni
Dec 7th, 2016, 05:45 AM
Did a quick search on the reasons and purposes of archiving and didn't find much at all. What prompted me was when I received an email informing me of an update to an archiving utility. I believe Windows users like you to Zip the file before sending.....at least that's my experience. With what little compression work most utilities do, what is the actual purpose of archiving files that aren't used very frequently? Does this method somehow protect them? From my perspective, it just seems like an extra step for no reason. Any comments?

polywog
Dec 7th, 2016, 08:11 AM
Four reasons, typically:

1) Vastly decreases file sizes for things that aren't already compressed (like text documents.) Images typically will compress very little, or actually be a slightly larger file size.
2) If there are several files to attach, it can be more convenient to provide a zip file, than several single attachments.
3) Some files cannot be attached; the mail client on the recipient end might remove the file, for instance if it's a shell script. Zipping the file prevents that.
4) You can password protect/encrypt a zip file, so if it's sensitive information, you can send the password protected zip, and provide the password through other means.

That said, OS X can make and read zip files, no 3rd party software needed.

csonni
Dec 7th, 2016, 12:51 PM
Thanks for that info. Just what I needed to know.
Just tried Archiver 3 to zip and compress using the highest compression setting. A MOV file and PDF file didn't change at all. A Word file did compress a bit but not very much. I'd really like to compress a certain number of files so email servers don't send them back. Archiver dies archive in "pieces", but I'm not sure what what needs to happen on the "user" end to decompress.

polywog
Dec 7th, 2016, 04:27 PM
Thanks for that info. Just what I needed to know.
Just tried Archiver 3 to zip and compress using the highest compression setting. A MOV file and PDF file didn't change at all. A Word file did compress a bit but not very much. I'd really like to compress a certain number of files so email servers don't send them back. Archiver dies archive in "pieces", but I'm not sure what what needs to happen on the "user" end to decompress.

All depends on the content: The contents of the MOV were likely already compressed. If the PDF was image heavy, it probably couldn't be compressed further (and I'm not sure that PDFs aren't compressed to start with.) Something like an excel sheet with no images in it could probably be compressed down 75%.

An extreme example; our server logs are typically 1GB compressed, but uncompressed the are over 10GB. They are nothing but text.

Zip splitting can be a pain; you'd be better served to drop the file somewhere like in Dropbox, then send a link to that.