On debian, i always recommend you install p7zip-full not p7zip
To extract with 7zip on linux, in order to maintain directory structure, use the x rather than the e, so the command to extract is
7za x file.7z
The file above would have been produced by a command such as
7z a -t7z -m0=lzma2 -mx=9 -mfb=64 -md=32m -ms=on archive.7z dir1
The above line adds all files from directory “dir1” to archive archive.7z using “ultra settings”