Comment 3 for bug 1899536

Prior releases had an issue where discovered devices were added to the collection, but not removed, which explains the accrual of these ephemeral virtual devices.

The 2.8 series addresses this issue in the logic for setting each machine's link-layer devices.

Where neither the provider nor the machine observes an interface, it is now deleted. So this should be a transient problem.

We are experimenting with indexes on the collection. The access-by-machine case is sped up greatly, but we're seeing worse performance where the index is not very selective, such as by model in this case.

This is only used by "juju status" though, so once the machines strangle out the devices, this should resolve.