Creating differential backups with 7-Zip
This is so great I'm shamelessly copying command lines for my own archive (aka this blog) - but also providing link to original.
7zip commands to create a backup of files
7za a c:\archive.7z c:\folder_to_archive
7za u c:\archive.7z c:\folder_to_archive -ms=off -mx=9 -t7z -u- -up0q3r2x2y2z0w2!c:\diff1.7z
p - File exists in archive, but is not matched with wildcard.q - File exists in archive, but doesn't exist on disk.r - File doesn't exist in archive, but exists on disk.x - File in archive is newer than the file on disk.y - File in archive is older than the file on disk.z - File in archive is same as the file on diskw - Can not be detected what file is newer (times are the same, sizes are different)
0 Ignore file (don't create item in new archive for this file) 1 Copy file (copy from old archive to new) 2 Compress (compress file from disk to new archive) 3 Create Anti-item (item that will delete file or directory during extracting). This feature is supported only in 7z format