Attention: Operators running the Nethermind client

Nethermind released version 2.0.0. It works with Aztec v5.2.0, but it changes how much L1 history a fresh sync keeps. If you run Nethermind or plan to upgrade to version 2.0.0, see your case below before you upgrade or resync.

What to do
- Upgrade in place from 1.39.x: safe. Your database and its settings do not change. Apply the Path 1 flags now and restart the Nethermind client.

- Resync on 2.0.0, now or later: set the history flags from the guide before the sync starts. With default settings, a fresh sync drops the L1 history back to the Aztec Rollup deploy block, 25428902, and the Aztec node stops syncing.

- Already resynced on 2.0.0: if the Aztec node syncs normally, no action. If it does not, resync with the Path 2 flags. Do not use Path 1 on this node — it discards your state and forces a full resync.

Geth, Besu, Reth, Erigon: not affected.

The guide has two configurations from the Nethermind team. Path 1 keeps your current database, with no resync. Path 2 moves to FlatDB, with downtime.

Nethermind 2.1.0 will include a dedicated Aztec mainnet config.