- mdb-env-copyfd env fdprocedure
Copy an LMDB environment to the specified file descriptor.
This function may be used to make a backup of an existing environment. No lockfile is created, since it gets recreated at need.
Note: This call can trigger significant file size growth if run in parallel with write transactions, because it employs a read-only transaction. See long-lived transactions under Caveats in the C API documentation.
- An environment handle returned by (mdb-env-create). It must have already been opened successfully.
- The filedescriptor to write the copy to. It must have already been opened for Write access.