Planning to run a full node. Have some questions.

[Beetkoin]

So I just downloaded Bitcoin Core.
But, when I ran the software, it says I have to download the entire 350GB blockchain.
This must be done whether I want to run a full node or a pruned node.

I want to ask: What happens in the event of a hard disk failure or a Windows reinstallation?
Do I have to go through the entire process of re-downloading and re-verifying the entire blockchain every time?
Or is there a way to download a pre-verified blockchain and just continue from whereever it left off?

I imagine that after setting up a full node with 350GB of data, I can just backup all the files.
And then if I reinstall Windows or my HDD fails, I can just restore the backup and then carry on from whichever block it was left off?
But if such a process can be done, then there must exist somewhere where I can downloaded a backed up version of a fully synced Bitcoin node, and then just carry on from there, without having to go through the tedious process of downloading and verifying from genesis myself?

[n0nce]

Yes, you can do a backup of your drive, best would be to encrypt it.
However, in this case you trust it, because you trust yourself and that your drive / node was fine and uncompromised.

Anything you download from the internet has a very high chance of being compromised and should not be trusted, so it might even be better not to run Bitcoin Core at all than downloading the blockchain via some sketchy Torrent.

That's the difference between downloading from a random person or downloading from your own trusted backup drive.
Another benefit of having a backup and a downside of downloading from a random server: your backup is local. So it's very fast over USB 3.0 or SATA. Downloading from a person on the internet won't be much faster than just downloading via Core from the Bitcoin network.

[DaveF]

You can shutdown a node and backup the data and copy it to a new install it will rescan the blocks just go from there.
There a a few discussions about it if you search.

BUT, if you are looking to do search the blockchain for things, you really should pull all the information into a database and search that.
RPC calls to core are not efficient. But there is an open source block explorer for it:
https://github.com/janoside/btc-rpc-explorer

There are several free open source block explorers out there that do need a DB.
https://github.com/mempool/mempool
https://github.com/iquidus/explorer

-Dave

[NeuroticFish]

I want to ask: What happens in the event of a hard disk failure or a Windows reinstallation?

If the HDD fails and the data is lost, obviously next time you'll have to re-download everything.
A word of advice, if your computer also has a SSD there are some tricks to make the whole process much much faster (at least temporarily keep the chainstate folder on SSD, maybe the indexes too).

Windows reinstallation is a different discussion. You can locate the data folders(or maybe you configured it from start to not be on c:), back them up before the OS reinstall, and next time use that folder as datadir. Then it will just continue/sync from the point you left it at the previous stop.

[Pmalek]

I want to ask: What happens in the event of a hard disk failure or a Windows reinstallation?
Do I have to go through the entire process of re-downloading and re-verifying the entire blockchain every time?

The same thing happens as with all your other software installed on that disk. You will have to re-install and re-download them when your operating system or the new hard drive is up and running.

Or is there a way to download a pre-verified blockchain and just continue from whereever it left off?

Where would that downloaded "pre-verified" blockchain come from? You still have to download it and let it sync with your Bitcoin Core. Why would you opt to download it from an unofficial source instead of using the official one? I understand that a second download and re-sync is a pain in the ass, but using someone else's data makes you potentially vulnerable to any modifications or malware that person could have intentionally put there.

[BlackHatCoiner]

But if such a process can be done, then there must exist somewhere where I can downloaded a backed up version of a fully synced Bitcoin node, and then just carry on from there, without having to go through the tedious process of downloading and verifying from genesis myself?

But, that's the whole point, man. Think of it.

If you DO NOT verify the blocks, how will you be sure that what you're viewing is your actual balance? By downloading and verifying Bitcoin Core in a clean machine such as a RPi, you ensure that the correct chain is yours once you finish syncing. It wouldn't differ (a lot) if you connected to someone else's node with downloading the blockchain from a third party.

The magic part is the verification.