Ceph performs extensive logging. Ceph can be configured to log directly through the central syslog
or rsyslog
service, but by default, it writes to local files. These are managed by the stock Linux logrotate
facility. Here's the default rotation stanza that the Ceph Jewel release installs.
# cat /etc/logrotate.d/ceph.logrotate/var/log/ceph/*.log { rotate 7 daily compress sharedscripts postrotate killall -q -1 ceph-mon ceph-mds ceph-osd ceph-fuse radosgw || true endscript missingok notifempty su root ceph}
The default retention is 7 days, which this author at times finds to be too short. To increase to four weeks, replace the 7 with 30, but be careful that the filesystem where /var/log
lives has adequate free space. As we note later in this chapter, Ceph logs can become quite large at times, and modestly-provisioned systems experience filled filesystems. To mitigate the risk of logjams (clogged logs?) it may be expedient to also add a maxsize...