7zip CLI - Best compression method (ultra LZMA2) - Chris Stretton

When using the 7zip CLI (7z) you may want to use the highest possible Ultra LZMA2 compression you can select in the 7zip UI.

The following flags will do this:

7z a -t7z <filename.7z> <source> -m0=lzma2 -mx=9

For example:

7z a -t7z myarchive.7z /path/to/myfiles -m0=lzma2 -mx=9

Breaking this down by argument:

• a tells 7z that we are adding files to an archive (new or existing)
• -t7z tells 7z that the type of archive we are creating is 7zip (as opposed to one of the other formats that the 7z CLI supports)
• -m0=lzma2 tells 7z to use LZMA2 compression
• -mx=9 tells 7z to use the highest possible compression setting for the selected method