...

The intention is that all devices should always be marked as synchronized unless someone is actively working on something. If you have to leave a device as unsynchronized and go do something else you should move the device to UNMANAGED state until you can get it back to synchronization so that it will not stop other people from working in the system. For SUNET there is also a Nagios alarm that will trigger if devices are left unsynchronized for more than an hour, so make sure to notify NOC (or make the device UNMANAGED to stop the alarm) if you leave something unsynchronized. If you mark devices as unsynchronized it's probably a good idea to make a note to come back and make them MANAGED again at some later point.

Unable to synchronize Arista device

If you get an error message like "napalm.base.exceptions.SessionLockedException: Session is already in use"

It means some other configuration session is pending on the device, maybe someone was trying to make local configuration changes on the device. To clear these config session SSH into the device and run "show configuration sessions" to see a list of any pending sessions, then enter the config sessions one by one using "configure session <name>" and then run "abort" to abort that configuration session.