# Revision history [back]

Hi again,

After doing more research it seems it's not a problem but a feature that isnt't supported by ceph or openstack. When using rbd as backend for ephemeral storage, when booting a VM the image is first downloaded from rbd glance pool on local storage then uploaded to ephemeral pool.

There is a ticket opened for implemetation on next openstack but it seems it got droped for juno. The only solution is either to restrict booting from glance and just boot from volume, or to use cephfs as a shared filesystem for ephemeral storage. Both options don't work for me so i guess i need to rethink this.

How does gluster compare to ceph?

Should i try it or should i keep using ceph and let the ephemeral storage be local?

Hi again,

After doing more research it seems it's not a problem but a feature that isnt't supported by ceph or openstack. When using rbd as backend for ephemeral storage, when booting a VM the image is first downloaded from rbd glance pool on local storage then uploaded to ephemeral pool.

There is a ticket opened for implemetation on next openstack but it seems it got droped for juno. The only solution is either to restrict booting from glance and just boot from volume, or to use cephfs as a shared filesystem for ephemeral storage. Both options don't work for me so i guess i need to rethink this.

How does gluster compare to ceph?

Should i try it or should i keep using ceph and let the ephemeral storage be local?

Update:

Got another problem that i can't resolve.

When i try to create a new instance i always get errors. Looking at nova-scheduler.log i can see the following error :

librados: client.cinder initialization error (2) No such file or directory


So from what i understand it's searching for the auth key in client.cinder, it's not there and can't authentificate with cephx. But from the ceph docs, nova-compute nodes don't need the ceph.client.cinder.keyring file as the secret is integrated into libvirt with virsh command. Did that but it's still asking for the file.

Any thoughts?