I've been backing up my MacBook Pro for 5 years using Carbon Copy Cloner. The full backup is on a partition of an external hard drive and there is a folder called
_CCC_Archives which I believe stores the diffs over time.
I have upgraded the OS at least once and I'm wondering what the implications of this are.
Since upgrading from something like Snow Leopard to Sierra some of my music projects fail to open, presumably due to incompatible software. Is there some way to boot my MacBook using a backup from an older OS, capture and export some files, then reboot the MacBook to the newer OS that I'm running?
Note that I have never backed up the Mac since upgrading the OS because I did not want to corrupt my backup if it would in fact be irreversibly corrupted by this change. So the backup drive only includes backups using Snow Leopard.
The setting I use for backups in CCC is called: "Maintain a backup (Archive modified and deleted files)"
And below this I see:
• Files and folders on "My Passport" that are not present on "Macintosh HD" will be archived.
• Previously backed up files on "My Passport" will be updated only if the size or modification date differs.
• Older versions of updated files will be archived.
• CCC will not prune archive content.