I'm in the process of migrating from a single replica set to a sharded topology. During the initial process, I selected a chunk size that was too small and resulted in ~50% of the chunks being flagged as "jumbo". To resolve this issue, I reconfigured the chunk size and followed the instructions here to clear the jumbo flag. However, after multiple days there are no further migrations happening. But, none of the chunks have been re-flagged as "jumbo" either.

I've tried manually stopping and restarting the balancer, but that didn't seem to have any effect. I tried manually editing data in some of the jumbo chunks but that didn't have any effect either.

Running sh.status() shows the following...

balancer:
    Currently enabled:  yes
    Currently running:  no
    Failed balancer rounds in last 5 attempts:  0
    Migration Results for the last 24 hours: 
            No recent migrations

This is especially problematic because the unmoved chunks are all on a shard that I'm attempting remove from the cluster. As such, leaving them where they are isn't an option.

It looks like there may be a mechanism to manually move chunks, but this isn't really a valid option for us either as there are ~45k chunks that need to be moved.

How do I get these chunks moved?