Paul Schenkeveld: Minimizing service windows on servers using NanoBSD + ZFS + jails
AsiaBSDCon 2010 paper session.
With more and more services and applications running on your average server, upgrading the operating system and application software becomes trickier and larger service windows are needed performing these upgrades.
Over the last four years the author has searched for means and methods to keep software up to date with minimum downtime and inconvenience for users and maximum consistency. The result is a model which combines the strength of NanoBSD, ZFS and jails to build servers where application upgrades result in downtime of only a few seconds and kernel upgrades only need the time to reboot without installing in (tampering with) the running system. This system is in production now for several months on about 10 servers at five different sites.