Creating and Splitting Transactions

Question

I left a node mining the testnet for a few days and got a bunch of coinbase transactions (close to 1200). I tried doing sweep_all [my address] but that failed: Error: payment id has invalid format, expected 16 of 64 character hex string: [my address]. That didn't make a lot of sense, so I tried the same command again. This time it failed with a different message: Error: failed to find a suitable way to split transactions.

So I tried the command transfer [my address] 16385 (that amount is the available balance without its decimal part) and got this: Error: failed to find a way to create transactions. Apparently the wallet is okay with the amount 16300 XMR, but it says it will have to split it into 9 transactions.

It seems that I am reaching some internal limits in building transactions. Could someone explain what is happening in the background, and how does splitting work?

Answer 1

So the transaction splitting function is not an anonymity thing, it's due to the dynamic block size limiter. Right now testnet is on the block median, and you're trying to create a transaction that is much larger than that block limit. So it tries to split the transaction up into several that fit into the block limit, but if it needs to create thousands of transactions to do that it would chew up your computer for ages, so it eventually wipes out. You would either have to wait until the block median is higher (unlikely any time soon on testnet) or you'd have to send it in smaller chunks:)

Answer 2

Perhaps there are not sufficient other transactions to participate in a ring on testnet for the amounts that you are trying to transact. Since a ring is required, no zero mixin transactions are allowed, you would have to try transactions in other (smaller) amounts.