Ceph’s default recovery settings are far too aggressive. Tone it down with the following in the [osd] section or it will impact client IO
osd_max_backfills = 1 osd_recovery_priority = 1 osd_client_op_priority = 63 osd_recovery_max_active = 1 osd_recovery_max_single_start = 1http://people.redhat.com/mskinner/rhug/q3.2015/Ceph_lessons.pptx
ドキュメントに反映されていないがデフォルト値が変わっている？
例 jewel 10.2.2
http://docs.ceph.com/docs/jewel/rados/configuration/osd-config-ref/
https://github.com/ceph/ceph/blob/jewel/src/common/config_opts.h
osd_max_backfills = 1 osd_recovery_max_active = 3 osd_recovery_op_priority = 3 osd_recovery_max_single_start = 1
