Ceph: Commands and Cheatsheet

Working with Ceph pools

Check the pools

[root@deploy-ext kolla]# ceph osd pool ls
device_health_metrics
images
volumes
backups
manila_data
manila_metadata
.rgw.root
default.rgw.log
default.rgw.control
default.rgw.meta
default.rgw.buckets.index
default.rgw.buckets.data
default.rgw.buckets.non-ec

Create a pool

ceph osd pool create dptest 128 128

[root@deploy-ext kolla]# rbd create --size 20480 --pool dptest vol01
[root@deploy-ext kolla]# rbd info dptest/vol01
rbd image 'vol01':
	size 20 GiB in 5120 objects
	order 22 (4 MiB objects)
	snapshot_count: 0
	id: 180b9ee11c2183
	block_name_prefix: rbd_data.180b9ee11c2183
	format: 2
	features: layering, exclusive-lock, object-map, fast-diff, deep-flatten
	op_features:
	flags:
	create_timestamp: Thu Sep  2 07:28:16 2021
	access_timestamp: Thu Sep  2 07:28:16 2021
	modify_timestamp: Thu Sep  2 07:28:16 2021

Resize a pool

[root@deploy-ext kolla]# rbd resize dptest/vol01 --size 51200
Resizing image: 100% complete...done.
[root@deploy-ext kolla]# rbd info dptest/vol01
rbd image 'vol01':
	size 50 GiB in 12800 objects
	order 22 (4 MiB objects)
	snapshot_count: 0
	id: 180b9ee11c2183
	block_name_prefix: rbd_data.180b9ee11c2183
	format: 2
	features: layering, exclusive-lock, object-map, fast-diff, deep-flatten
	op_features:
	flags:
	create_timestamp: Thu Sep  2 07:28:16 2021
	access_timestamp: Thu Sep  2 07:28:16 2021
	modify_timestamp: Thu Sep  2 07:28:16 2021

Map a device / mount a volume

[root@deploy-ext kolla]# rbd map dptest/vol01
/dev/rbd0

[root@deploy-ext kolla]# mkfs.xfs /dev/rbd/dptest/vol01
[root@deploy-ext kolla]# mount /dev/rbd/dptest/vol01 ./ceph-vol/
[root@deploy-ext kolla]# df -h | grep ceph-vol
/dev/rbd0             50G  390M   50G   1% /root/kolla/ceph-vol

Ceph maintenance

Stop rebalancing (useful for rebooting systems etc)

ceph osd set noout; ceph osd set norebalance

# perform reboot / maintenance ;

Ceph locks

# here we had an instance loose connectivity to ceph
# in openstack set state to active (node reset-state --active UUID)
# openstack server stop UUID
# then remove the lock as below
# then we could snapshot
ceph osd unset norebalance; ceph osd unset noout

# checking volume info (openstack env timed out, went into error
root@str-237:~# rbd info  volumes/volume-417feeef-d79d-4a31-af13-f1bee971284b
rbd image 'volume-417feeef-d79d-4a31-af13-f1bee971284b':
	size 3.9 TiB in 512000 objects
	order 23 (8 MiB objects)
	snapshot_count: 0
	id: 5ba8f5a87a6a8
	block_name_prefix: rbd_data.5ba8f5a87a6a8
	format: 2
	features: layering, exclusive-lock, object-map, fast-diff, deep-flatten
	op_features:
	flags:
	create_timestamp: Tue Feb 14 19:37:14 2023
	access_timestamp: Thu Feb 23 19:18:17 2023
	modify_timestamp: Thu Feb 23 19:18:21 2023
	parent: volumes/volume-7aedaaa5-f547-401a-b4cb-1d2271eb1c7d@snapshot-509cbdc3-4eeb-4acf-ae0e-0cf64aa9f824
	overlap: 3.9 TiB

root@str-237:~# rbd lock ls volumes/volume-417feeef-d79d-4a31-af13-f1bee971284b
There is 1 exclusive lock on this image.
Locker          ID                    Address
client.6007059  auto 139760250032464  10.16.31.12:0/3416256037


root@str-237:~# rbd lock rm volumes/volume-417feeef-d79d-4a31-af13-f1bee971284b "auto 139760250032464" client.6007059

root@str-237:~# rbd lock ls volumes/volume-417feeef-d79d-4a31-af13-f1bee971284b