Time Machine Slow Backup

System: OS X Snow Leopard (10.6.8)

Symptom: Backing up minor changes (few MB) would take a really long time, and the rate of backup would be on the order of KB/s. The system tries to prepare hundreds of thousands of files. The Time Machine drive had a fresh full backup.

Solution:

  1. Delete /.fseventsd on your startup drive or move it to another location:
    mv /.fseventsd /.fseventsd.bak
  2. Reboot
  3. Start a Time Machine backup
    Speculation: When Time Machine can’t find /.fseventsd, I’m guessing it does a deep traversal (according to my system.log), which I take to mean scanning for changed files, and then rebuilding the metadata for /.fseventsd. More discussion at https://discussions.apple.com/message/18923411?ac_cid=tw123456.