High kernel CPU usage caused by btrfs-balance
May also be a fragmentation issue.
The system is intermittently unresponsive. When the system is unresponsive, there is often high disk usage and high kernel CPU usage. The system is unresponsive while btrfs-balance, btrfs-trim, or other automated filesystem maintenance is running.
The bug is not present when btrfs quotas are disabled. Snapper's limits must not have ranges when quotas are disabled.
sudo btrfs quota disable /
sudo snapper set-config QGROUP= NUMBER_LIMIT=10 NUMBER_LIMIT_IMPORTANT=10