Before starting to cover some recovery techniques, it is important to cover some points discussed in Chapter 1, Planning for Ceph. Disaster-recovery should be seen as a last resort; the recovery guides in this chapter should not be relied upon as a replacement for adhering to best practices.

First, make sure you have working and tested backups of your data; in the event of an outage, you will feel a million times more relaxed if you know that in the worst cases, you can fall back to backups. While an outage may cause discomfort for your users or customers, informing them that their data, which they had entrusted you with, is now gone is far worse. Also, just because you have a backup system in place, does not mean you should blindly put your trust in it. Regular test restores will mean that you will be able to rely on them when needed.

Make sure you follow some design principles also mentioned in Chapter 1, Planning for Ceph. Don't use configuration options, such as nobarrier, and strongly consider the replication level you use with in Ceph to protect your data. The chances of data loss are strongly linked to the redundancy level configured in Ceph, so careful planning is advised here.