You must have an account’s keyfile to be able to send any transaction from that account. Keyfiles are found in the keystore subdirectory of your Ethereum node’s data directory. The default data directory locations are platform specific:

  • Windows: C:\Users\username\%appdata%\Roaming\Ethereum\keystore
  • Linux: ~/.ethereum/keystore
  • Mac: ~/Library/Ethereum/keystore

To backup your keyfiles (accounts), copy either the individual keyfiles within the keystoresubdirectory or copy the entire keystore folder.

To restore your keyfiles (accounts), copy the keyfiles back into the keystore subdirectory, where they were originally.