On Tue, May 28, 2019, 8:29 AM Bernd Bausch <berndbausch@gmail.com> wrote:

Thanks for clarifying this Erik. Let me point out then that the release notes [1] are worded rather unequivocally, and what you are saying contradicts them:

RBD driver has added multiattach support. It should be noted that replication and multiattach are mutually exclusive, so a single RBD volume can only be configured to support one of these features at a time. Additionally, RBD image features are not preserved which prevents a volume being retyped from multiattach to another type. This limitation is temporary and will be addressed soon.

Bernd.

I haven't even looked at Stein yet so I could be wrong, but I thin this is referring to replication like RBD mirroring. There's still an issue in Ceph, as far as I know, where ceph's object replication would have a problem with multi-attach. I haven't come across any Ceph release note to say this has been addressed.

Hopefully someone from the Cinder team can straighten us out.

-Erik

On 5/28/2019 11:30 AM, Erik McCormick wrote:

There isn't really a Ceph multi-attach feature using Cinder

[1] https://docs.openstack.org/releasenotes/cinder/stein.html