Back up Mac using CarbonCopyCloner with command line only?
Boot to Single User Mode with one (empty) backup drive attached. Execute the indicated standard commands:


/sbin/fsck -fy
/sbin/mount -uw /
Get the disk identifier of the external backup drive:

gpt -r show disk1 #(or disk2, disk3) search for the proper drive with gpt because *diskutil* won't work in SU mode

Mount the external drive's main partition (e.g. disk1s2) to /Volumes/externaldrive and create a new folder:

mkdir /Volumes/externaldrive
/sbin/mount -o nosuid -w -t hfs /dev/disk1s2 /Volumes/externaldrive
mkdir /Volumes/externaldrive/new_backupdir

Backup your main drive with rsync e.g:

rsync -aE --exclude='/Volumes' / /Volumes/externaldrive/new_backupdir


If you want to backup only the folder /Users modify the rsync command accordingly. Please check man rsync for the appropriate options. Some of the useful options (like -v) don't work in SU mode - at least for me. Depending on your system, the options set and the excluded items the rsync command will yield some minor errors.




This backup isn't bootable per se. You may create a bootable backup though by backing up to the root of the external drive and blessing the appropriate boot.efi.