user179: While setting up Cardano Stake Pool, we need to have at least 2 nodes: one for Relay, another for Block Producing (BP).
This Relay node downloads the whole blockchain, and the BP Node will connect only to Relay node and it will sync the blockchain from the Relay node.
My question is, since both of these nodes are in same network, I feel like it's duplicate information downloaded twice. Is there any way by which we can share the same blockchain database for both of these nodes?

user382: It's impossible to share the same state directory. But if your concern is primarily disk space, you can use filesystem deduplication. For example I have a dedicated zfs volume with dedup setup I use to limit disk usage for multiple nodes ran on same machine for test networks. I wouldn't recommend doing this on mainnet though as running a bunch of nodes on the same host defeats the purpose.

user28: This is not possible, as both nodes are two different blockchain nodes and might have different views of the network in forks as in transactions in the mempool.

user161: You can't share the underlying data folder so will need a copy for each node. However, you can pre-seed them by syncing one, then duplicating its db folder into the others, so that when they start up they do not need to re-sync and validate the entire chain.
If you can get a copy of the db folder form a trusted source, you could potentially speed up the very first sync too (since downloading a compressed version of that will be much faster than syncing and validating the whole chain).

179: <p>While setting up Cardano Stake Pool, we need to have at least 2 nodes: one for Relay, another for Block Producing (BP).</p>
<p>This Relay node downloads the whole blockchain, and the BP Node will connect only to Relay node and it will sync the blockchain from the Relay node.</p>
<p>My question is, since both of these nodes are in same network, I feel like it's duplicate information downloaded twice. Is there any way by which we can share the same blockchain database for both of these nodes?</p>
 382: <p>It's impossible to share the same state directory. But if your concern is primarily disk space, you can use filesystem deduplication. For example I have a dedicated zfs volume with dedup setup I use to limit disk usage for multiple nodes ran on same machine for test networks. I wouldn't recommend doing this on mainnet though as running a bunch of nodes on the same host defeats the purpose.</p>
 28: <p>This is not possible, as both nodes are two different blockchain nodes and might have different views of the network in forks as in transactions in the mempool.</p>
 161: <p>You can't share the underlying data folder so will need a copy for each node. However, you can pre-seed them by syncing one, then duplicating its <code>db</code> folder into the others, so that when they start up they do not need to re-sync and validate the entire chain.</p>
<p>If you can get a copy of the <code>db</code> folder form a trusted source, you could potentially speed up the very first sync too (since downloading a compressed version of that will be much faster than syncing and validating the whole chain).</p>
