Using 7z to create archives is OK, but when you use tar, you preserve all file-specific information such as ownership, perms, etc. If that's important to you, this is a better way to do it.

Sometimes it is handy to be able to list contents of a tar file within a compressed archive, such as 7Zip in this instance, without having to extract the archive first. This is especially helpful when dealing with larger sized files.

Creates a solid archive with the highest possible compression (Ultra). Advantage of 7z is that it will use all the processor cores to create the archive. (Ok. at least version 9.04 does) Show Sample Output

These re the best option combination that works fine for compressing my database dumps. It's possible that there are another option or value that might improve the compression ratio, by these are the ones that worked, the syntax for 7zr it's a little messy...

Compress files or a directory to xz format. XZ has superior and faster compression than bzip2 in most cases. XZ is superior to 7zip format because it can save file permissions and other metadata data.

compress directory archive with xz compression, if tar doesn't have the -J option (OSX tar doesn't have -J)

Create a 7zip archive named "some_directory.7z" and adds to it the directory "some_directory". The `-mhe=on` is for header encryption, basically it mangles the file names so no one knows whats inside the 7z. If -mhe=on wasn't included, then a person without the password would still be able to view the file names inside the 7z. Having this option ensures confidentiality. To ensure the result is small use lzma2, level 9 compression. Lzma2 fast bytes range from 5 to 272, the higher the number the more aggressive it is at finding repetitive bytes that can be added to the dictionary. Here the fast bytes are set to 64 bytes and the dictionary is 32 MB. Depending on your purposes (the directory size and desired file size), you can be more aggressive with these values. Lastly, `-ms=on` just says concatenate all the individual files and treat them as a singular file when compressing. This leads to a higher compression ratio generally.