Why does P2Pool need a fully synced monerod?

P2Pool needs a fully synced monerod so it can build mining work on the current Monero blockchain and submit any block you find right away. If the node is still catching up, P2Pool cannot reliably get current mining work, and you could waste computing power on blocks the network will not accept.

What monerod supplies to P2Pool

monerod is the program that runs a Monero node. A node downloads and checks the blockchain—the shared history of Monero blocks and transactions—and keeps up with new blocks as they arrive.

P2Pool handles a different job. It coordinates miners through a separate sharechain, a record of smaller mining proofs called shares. Those shares determine how rewards are divided when P2Pool finds a Monero block.

The sharechain does not replace the Monero blockchain. P2Pool still needs monerod to supply:

• The latest accepted Monero block to build on.
• The current mining difficulty, which sets how hard a valid block is to find.
• A block template, the starting information for a candidate block.
• A way to submit a discovered block to the Monero network.

In short, P2Pool coordinates your mining, while monerod supplies the verified Monero chain information behind it.

Why an unfinished sync is not enough

Imagine your node has downloaded nearly all the blockchain but is still several hours behind. Its records may be valid so far, but they do not describe the current end of the chain.

That matters because each new block points back to a particular previous block. Mining work built on an old block does not automatically become useful after your node catches up. The work belongs to that older candidate block.

Monero produces a block about every two minutes, and mining difficulty adjusts every block. Missing recent blocks therefore means missing information that directly affects your mining work.

Depending on its state, a syncing node may refuse to provide a usable block template. Even if you obtain outdated work, it is not a reliable route to accepted blocks or rewards. Being “almost synced” is not enough to start productive mining.

Staying synced matters after startup

Full sync is not just a box you tick once. Your node must remain connected and keep receiving new blocks.

P2Pool uses the node’s RPC interface, a way for programs to request information and submit blocks. It also uses ZMQ notifications, messages that quickly announce relevant changes, including newly received blocks.

If those connections fail, or your node falls behind, P2Pool may not refresh its mining work promptly. A working sharechain connection alone cannot fix that: P2Pool also needs a current view of Monero itself.

Do you need your own full blockchain copy?

You need access to a suitable, synced monerod; it does not necessarily have to run on your mining computer. A remote node can work if it provides the required interfaces. Not every public node does.

Running your own node gives you more control and avoids relying on someone else’s uptime and chain information.

You can also use a pruned node, which saves storage by discarding some older transaction data after checking it. Pruned does not mean partly synced: it must still catch up to the current chain.

The bottom line

P2Pool’s sharechain tracks mining contributions, not Monero’s current blockchain state. A fully synced, reachable monerod provides the current, verified foundation your mining work needs.