7

If you give Bitcoin Core a fully populated data directory, it will use it without any validation. However, if you only give it the blocks/ subdirectory, it will fully validate it to recreate the chainstate directory, exactly as if it were received over the network.


5

By default the RPC interface is only exposed to localhost (127.0.0.1 and ::1), not to the world. In that setting, you need an RPC password only to protect against untrusted local users on your system (unless you're somehow tunneling the RPC port 8332 out). That said, why do you have an rpcpassword at all? If you're only going to use bitcoin-cli for example ...


5

Will the miner simply ignore that block? Yes, the block will be just ignored by the miner. how will the miner update to A-B-C-D-E (step by step)? When the miner's node gets online and start connecting to peers, it will start a “handshake” by transmitting a version message, which contains all basic identifying information, including BestHeight (the ...


4

That's because although the Bitcoin blockchain has a current height of 574080, your full node has synced until 195807 (the output "blocks": 195807 after running getblockchaininfo command). Block 195876, the one that you are querying, has not synced yet on your node. As you said, you have just installed Bitcoin Core. It take many hours (or sometimes days ...


3

The progress number is the ratio between the total number of transactions in the active (validated) chain, and the expected total number of transactions at the current point in time. The latter is estimated based on statistics that are hardcoded in the Bitcoin Core source code, and updated every major release. For example in version v0.19.0, the source code,...


3

The wallet itself is still downloading the block and is 3 years and 29 months behind. Does this mean I must wait until this finishes before it shows up? Yes, in order to understand the current state of the network (which includes the transaction that you received funds in), your node will need to work through the blockchain history. Otherwise, your node ...


3

When a new node joins the network, it will look up nodes from the DNS seeds. It'll reach out to multiple nodes it hears about and ask them for more peers in turn. The new node asks each of their peers for their best chaintip and then starts sychronizing the headers of the best chaintip it hears about first. A block header is only 80 bytes (tiny in comparison ...


3

The RPC interface is not exposed to anything except localhost by default. So other people on your network, nor people on the internet, can access it unless you have explicitly enabled outside access using rpcbind=<ip> and rpcallowip=<ip>. So even using an insecure rpcpassword should be safe. Furthermore, it is completely useless if you don't also ...


3

The problem is less so with validating the blocks and more to do with bandwidth constraints and the time it takes to write blocks to disk and update the databases. As you sync more of the blockchain, the blocks become bigger and contain more transaction inputs and outputs. The outputs need to be added to the chainstate database and the inputs removed. This ...


2

You are allocating far too much dbcache. If you allocate 4000 MB to the dbcache, you will use up all of your RAM and it will crash. Your operating system needs RAM, Bitcoin Core itself needs RAM outside of the dbcache. I would highly recommend that you do not set a dbcache at all as 4 GB is really not enough RAM to handle a larger dbcache, Bitcoin Core's ...


2

From my own experience, running ABCore on a Nexus 5X, Android is too eager to kill processes that use a large amount of memory on systems with less than 3 GB.


2

The recommended way is to use the -connect option. You can do -connect=0 or -noconnect (they mean the same thing) and Bitcoin Core will not try to automatically connect to any other node.


2

where is my bitcoin money, when downloading is failed. Your money is in the Blockchain (loosely speaking). It is not affected by the state of your wallet. When your wallet finishes collecting its own copy of the public Blockchain (synchronisation), it will be able to show you the amount of money you control. Some explanation: A wallet does two things. ...


2

Your node will just ask its peers for blocks. It actually does the same thing it does for the initial sync. It starts with what it currently considers to be the chain tip (in initial sync, that's the genesis block). From there, it connects to other nodes and asks those nodes for more block headers starting with the block at its own chain tip. Typically, that ...


2

A reindex will not redownload the block. However, after safely shutting down Bitcoin Core, you can delete the block file containing that block. When you start it again, you will need to reindex, but once it gets to the blocks that you deleted, it will redownload them.


1

As you've discovered, Bitcoin Core is almost optimally non-performant on shared servers. The majority of the work done is on a single core, so measuring the total utilization of the CPU is not a good measure. Database operations are necessarily single threaded, and the majority of the work in the early parts of the chain are entirely consumed by this. ...


1

Yes a full node downloads and verifies all blocks starting from the genesis block. Not on every startup though, the state is efficiently stored and read back into memory on startup (with some rechecking of the last X blocks as a sanity check against corruption). For finding the right chain, it starts with downloading the headers first, with which it can ...


1

Does bitcoin qt need to synch with the network before it will notice the change has been received It won't know about the change transaction until it has processed the block containing that transaction. Your change transaction is in a recent block, your bitcoin software is still catching up earlier blocks and hasn't retrieved that recent block yet. ...


1

Zapier is a great tool that you can use to accomplish actions like mail download links, send SMS, push notification to slack etc. You can setup bitcoin payment as trigger and then configure action to do.


Only top voted, non community-wiki answers of a minimum length are eligible