Ceph

what does it mean?

osd            object storage daemon
rados          Reliable Autonomic Distributed Object Store
rbd            Rados Block Device

ceph

Status of ceph

ceph -s

Disk usage

ceph df

Check placement group stats

ceph pg dump

View the CRUSH map

ceph osd tree

Create or remove OSDs

ceph osd create
ceph osd rm

Get du from block devices in pool named *rbd*

POOL=$(ceph osd pool ls | grep rbd) ; for i in $(rbd -p $POOL ls | xargs) ; do echo $POOL $i ; rbd -p $POOL du $i 2>/dev/null ; done

access ceph in odf

oc rsh -n openshift-storage $(oc get pods -n openshift-storage -o name -l app=rook-ceph-operator)
export CEPH_ARGS='-c /var/lib/rook/openshift-storage/openshift-storage.config'

list osd pools

ceph osd pool ls
ceph osd pool autoscale-status
ceph config dump
# disable autoscaling
ceph osd pool ls | while read i ; do echo '*' $i ; ceph osd pool set $i pg_autoscale_mode off ; done
# Look to see how much data is being used for pg:s.
# Number of PGLog Entries, size of PGLog data in megabytes, and Average size of each PGLog item
for i in 0 1 2 ; do echo '*' $i ; osdid=$i ; ceph tell osd.$osdid dump_mempools | jq -r '.mempool.by_pool.osd_pglog | [ .items, .bytes /1024/1024, .bytes / .items ] | @csv' ;done
ceph df