Back up Mac using CarbonCopyCloner with command line only?

Question

Background:

I never expected to have only command line access to my Mac, but the day has arrived! :) Due to a video card problem, any attempt to boot the normal OS or recovery partition results in a kernel panic. However, I can boot into Single User mode! (The screen has a bunch of green horizontal lines through it every other pixel, but it is still readable.)

I have checked and verified that my data is intact. I have a Genius Bar appointment to get the video card replaced.

I have a couple of backup drives on which I have CarbonCopyCloner backups of my computer, however these are out of date.

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I want to back up my Mac from the Single User Mode command line using CarbonCopyCloner before I take it for the video card replacement.

(I found this link on the ccc tool, but I don't have ccc 4.)

Questions are:

1. How can I use CarbonCopyCloner 3.5.7 from the Single User Mode command line to update one of my full backups before I take the machine in for service?
2. If this can't be done from the command line with this version of CCC, how else could I back up all data before taking it in for service (from Single User mode)?

Answer 1

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.

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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.

Answer 2

If you are OK with not using CCC to make the backup you could use the command line to create a regular disk image. Not sure if this is something that will work for you, but I don't have any knowledge as far as CCC goes.

sudo hdiutil create ~/Desktop/{disk image name}.dmg -srcdevice /dev/{disk identifier}