The defrag variable is not being reinitialized during glusterd restart. This means that if glusterd goes down or needs to be restarted while the following processes are running, it does not reconnect to these processes after restarting:
This results in these processes continuing to run without communicating with glusterd. Therefore, any operation that requires communication between these processes and glusterd fails.
To work around this issue, stop or kill the rebalance, tier, or remove-brick process before restarting glusterd. This ensures that a new process is spawned when glusterd restarts.