[Ethereum] Parity — How to delete DB and resync it

Two methods are possible:

1. Import/ Export

On 1.2 and above, use Geth's export feature along with Parity's import:

mkfifo /tmp/chain.rlp && geth export /tmp/chain.rlp & sleep 1 && parity import /tmp/chain.rlp

2. Syncing

Basically you would have to run a geth node with your private chain and fire up a parity node that connects to your network and syncs it.
Since Parity 1.3 there is a feature called SnapSync, but I doubt it can be used with geth.

Further details:| https://github.com/ethcore/parity/wiki/Importing%20a%20chain%20from%20Geth

Not sure if I get your question correctly. Assuming you have a private network running with 5 clients on network ID 13337 and myGenesis.json chain configuration.

• enode://0000..0001@192.168.178.101:36541
• enode://0000..0002@192.168.178.102:36542
• enode://0000..0003@192.168.178.103:36543
• enode://0000..0004@192.168.178.104:36544
• enode://0000..0005@192.168.178.105:36545

Add these nodes to a file, let's say myPrivateNetwork.txt, one entry per line:

enode://0000..0001@192.168.178.101:36541
enode://0000..0002@192.168.178.102:36542
enode://0000..0003@192.168.178.103:36543
enode://0000..0004@192.168.178.104:36544
enode://0000..0005@192.168.178.105:36545

And subsequently, run Parity with --chain myGenesis.json --network-id 13337 --reserved-peers myPrivateNetwork.txt --reserved-only. Or add it to the config file:

[parity]
chain = "myGenesis.json"

[network]
id = 13337
reserved_only = true
reserved_peers = "./myPrivateNetwork.txt"

This will establish a private network containing only your nodes:

--reserved-peers FILE        Provide a file containing enodes, one per line.
                             These nodes will always have a reserved slot on top
                             of the normal maximum peers. (default: None)
--reserved-only              Connect only to reserved nodes. (default: false)

Adding reserved peers also works from the Web3 console by issuing:

api.parity.addReservedPeer('enode://0000..0007@192.168.178.107:36547')

Note, that you have to enable the parity json rpc api.

You can also run a private development chain with parity --chain dev.