Comment 7 for bug 2007976

I think .juju-persistent-config is broken in some of the release channels(stable channel looks fine). I can easily reproduce it on quincy/stable:

https://pastebin.ubuntu.com/p/mvWdTprj7g/

The .juju-persistent-config file not update after config change.

So the charm can still read previous config, but it's the wrong value, which will broke the process in ceph upgrade because we use previous config to compare the version.

I need to trace to check where make it broken, currently stable channel is fine, so it's seems like the bug in charm's code.