Hi, I installed OpenStack RDO on one node. The size of the root OS was 460GB (as shown in the horizon dashboard). I launched 18 instances with a volume size of 20GB. In the overview part of the dashboard, it shows I used 360GB of volume storage. There is no data in instances (just OS files). But when I try to launch a new instance with the size of 20GB it errors on creating volume. I checked the nova and cinder logs but they didn't contain something special about the error.

Just for a test, I tried to create volumes with the size of 15GB and 10GB and no error happened, so I guess we have a capacity problem. I checked the compute OS storage status, but it has so much capacity! I guess OpenStack configure just a part of the compute disk for volumes and I don't know where OpenStack store them. I only found a path in the /dev/cinder-volumes that contains volume ids but it's just a link!

Note: I found this error on cinder scheduler :

Failed to run task cinder.scheduler.flows.create_volume.ScheduleCreateVolumeTask;volume:create: No valid backend was found

Here is the result of the command vgs:

VG                        #PV #LV #SN Attr   VSize    VFree   
  centos                      1   3   0 wz--n- <464.76g    4.00m
  centos_host-192-168-0-199   1   4   0 wz--n-  <19.00g       0 
  cinder-volumes              1  20   0 wz--n-  <20.60g 1012.00m

How can I increase the storage of cinder volumes?