Edit /etc/modprobe.d/zfs.conf
# Set use max memory at half of system memory (ex. 4GB/2) options zfs zfs_arc_max=2147483648 # Increase scrub/resilver worker options zfs zfs_vdev_scrub_min_active=24 options zfs zfs_vdev_scrub_max_active=64 # Increase sync write options zfs zfs_vdev_sync_write_min_active=8 options zfs zfs_vdev_sync_write_max_active=32 # Increase sync reads options zfs zfs_vdev_sync_read_min_active=8 options zfs zfs_vdev_sync_read_max_active=32 # Increase async reads options zfs zfs_vdev_async_read_min_active=8 options zfs zfs_vdev_async_read_max_active=32 # Increase async write options zfs zfs_vdev_async_write_min_active=8 options zfs zfs_vdev_async_write_max_active=32
Save and reboot system to active configuration