Use borg and APFS snapshot to back up your Mac.
Q: Why not use Time Machine directly?
TL;DR: Because Time Machine is slow and problematic.
Time Machine is terribly slow. It seems to take forever for backup my 256G MacBook, even if I have 1Gbps Ethernet attached.
There are many cases that TM is always keeping backup but never succeed. There are cases that TM backups cannot be restored. I don't want to put my trust in such an unstable software.
Q: How does this work?
Thanks to APFS, we can easily take snapshots for filesystem now.
This command works by first using tmutil localsnapshot to create a snapshot of your root filesystem.
Then use mount to mount it to a path, and backup it with borg. Due to borg's deduplication mechanism,
it's recommended that you mount snapshots to the same path every time.
I have written a bash script to do
basically the same thing. You may consult it if you want to know more. Please note due to the lack of flock(1),
this bash script can be run in parallel and cause problems.