Uploading image to glance fails with "500 internal Server Error"

Issue

• Uploading an image to glance fails with below error message.

$ glance --os-image-api-version 2 image-create --disk-format vmdk --container-format bare --file myvmdk.vmdk
500 Internal Server Error: The server has either erred or is incapable of performing the requested operation. (HTTP 500)

• Glance API logs (/var/log/glance/glance-api.log) shows below error message during this time.

2017-02-01 16:12:55.384 37136 ERROR glance_store._drivers.rbd [req-8f5b5bb1-8237-41b4-a963-2db43b151ce9 d5cfb2b27dff4f848b0f5dfb6ebabd1b b38ed88a3442438bad03a391302cd2dc - - -] Error connecting to ceph cluster.
2017-02-01 16:12:55.384 37136 ERROR glance_store._drivers.rbd Traceback (most recent call last):
2017-02-01 16:12:55.384 37136 ERROR glance_store._drivers.rbd   File "/usr/lib/python2.7/site-packages/glance_store/_drivers/rbd.py", line 203, in get_connection
2017-02-01 16:12:55.384 37136 ERROR glance_store._drivers.rbd     client.connect(timeout=self.connect_timeout)
2017-02-01 16:12:55.384 37136 ERROR glance_store._drivers.rbd   File "rados.pyx", line 785, in rados.Rados.connect (rados.c:8969)
2017-02-01 16:12:55.384 37136 ERROR glance_store._drivers.rbd Error: error connecting to the cluster: error code 95
2017-02-01 16:12:55.384 37136 ERROR glance_store._drivers.rbd 
2017-02-01 16:12:55.388 37136 ERROR glance.api.v2.image_data [req-8f5b5bb1-8237-41b4-a963-2db43b151ce9 d5cfb2b27dff4f848b0f5dfb6ebabd1b b38ed88a3442438bad03a391302cd2dc - - -] Failed to upload image data due to internal error
2017-02-01 16:12:55.388 37136 ERROR glance.api.v2.image_data Traceback (most recent call last):