savemempool
Dumps the mempool to disk. It will fail until the previous dump is fully loaded.
Examples:
> bitcoin-cli savemempool
> curl --user myusername --data-binary '{"jsonrpc": "1.0", "id":"curltest", "method": "savemempool", "params": [] }' -H 'content-type: text/plain;' http://127.0.0.1:8332/