Arbitrum One and Arbitrum Rinkeby testnet have both been upgraded to Nitro, the latest Arbitrum tech stack; "Arbitrum Classic" is our term for the old, pre-Nitro tech stack. The Nitro node databases have the raw data of all blocks, including pre-Nitro blocks. However, Nitro nodes cannot execute anything on pre-Nitro blocks. Arbitrum Nova started as a Nitro chain, so it has no classic blocks. The following commands require an Arbitrum Classic node to execute data on pre-Nitro blocks.
Please find more information here.
You have to run your nitro node with
--node.archive Retain past block state
--node.rpc.classic-redirect=<classic node RPC> If set, will redirect archive requests for pre-nitro blocks to the designated RPC, which should be an Arbitrum Classic node with archive database. Only valid for Arbitrum One or Rinkeby Testnet
Note: it's only if you want to use the above calls to execute data on the classic node. All the raw data is available from the Nitro node itself.