-prune=
       Reduce storage requirements by enabling pruning (deleting) of old
       blocks. This allows the pruneblockchain RPC to be called to
       delete specific blocks, and enables automatic pruning of old
       blocks if a target size in MiB is provided. This mode is
       incompatible with -txindex and -rescan. Warning: Reverting this
       setting requires re-downloading the entire blockchain. (default:
       0 = disable pruning blocks, 1 = allow manual pruning via RPC,
       >550 = automatically prune block files to stay under the
       specified target size in MiB)