Ceph: Designing and Implementing Scalable Storage Systems

Injection

Earlier in this chapter we discussed Ceph settings defined in the ceph.conf config file. When present as each Ceph daemon starts up, these settings override compiled-in defaults. To borrow a term from the network router world, ceph.conf is an example of stored, startup or saved config. As circumstances cause us to adjust or augment these explicit file-based settings we can effect them by rolling restarts of Ceph daemon processes or even server reboots.

While Ceph's resilient and fault-tolerant architecture affords us the flexibility to carefully apply configuration changes by service restarts, there is faster and less disruptive method: injection.

Ceph's injection mechanism is a handy and nearly immediate way to affect Ceph's ...