System Updates

• problem domain

  • need to apply kernel updates without a post
  • restart updated services when security critical
  • minimise downtime (ideally zero)
  • no need to batch updates together
  • rolling updates
  • how many old states, how far can we roll back?

• baserock currently use btrfs volumes as state partitions

• snappy, project atomic, baserock all currently involve reboot
• current, last, factory, developer mode
• filesystem-layer atomic (or directory swap)
• systemd can map processes to services - is it possible to get services back
• lvm on ubi to do A/B/F
• ostree?
• diff transmission