Ceph » Orchestrator

host labels are not stored in the order entered or a logical order like alphabetically. they stored in a randomized order.

[ceph: root@vm-00 /]# ceph orch host add vm-01 --labels=a,b,c,d,c
Added host 'vm-01'
[ceph: root@vm-00 /]# ceph orch host ls
HOST   ADDR             LABELS   STATUS  
vm-00  192.168.122.220                   
vm-01  vm-01            b a d c          
vm-02  vm-02                             
[ceph: root@vm-00 /]#

the list of labels is stored as set temporarily to remove duplicates here https://github.com/ceph/ceph/blob/master/src/python-common/ceph/deployment/hostspec.py#L48,#L57

this is the side effect of using sets to remove duplicates it randomizes the order.