Can I import the whole blockchain from Bitcoin Core into Bitcoin ABC?

[gwodus]

I would like to use Bitcoin ABC. However I'd like to avoid it that ABC has to download the whole blockchain again. The last time I did this with core it took almost a week.

Can I just import or copy the current chain from a bitcoin core instance which I have running? Note that my core instance has already caught up past Aug. 1st. Would this be a problem?

Thanks!

[pereira4]

I would like to use Bitcoin ABC. However I'd like to avoid it that ABC has to download the whole blockchain again. The last time I did this with core it took almost a week.

Can I just import or copy the current chain from a bitcoin core instance which I have running? Note that my core instance has already caught up past Aug. 1st. Would this be a problem?

Thanks!

I think you can. That is what I was planning to do. As long as you running a Bitcoin Core full node, I think any version would do, at the end of the day it's the same blockchain, the format of the files have been always the same, but ideally you want to export it from the most recent Bitcoin Core version.

Just copy paste the block files on Bitcoin ABC client, when you open it, you will have to validate the entire chain, but without having to download it. I still didn't try but im afraid it will be insanely slow on my computer, you will need a strong CPU to validate in a reasoanble amount of time.

[gwodus]

I think you can. That is what I was planning to do. As long as you running a Bitcoin Core full node, I think any version would do, at the end of the day it's the same blockchain, the format of the files have been always the same, but ideally you want to export it from the most recent Bitcoin Core version.

Just copy paste the block files on Bitcoin ABC client, when you open it, you will have to validate the entire chain, but without having to download it. I still didn't try but im afraid it will be insanely slow on my computer, you will need a strong CPU to validate in a reasoanble amount of time.

Ok, I am copying the blocks right now. I will let you know how it worked out. Unfortunately my PC is a five year old i7. And also by SSD does not have enough free space for another chain. So the slow HDD has to make do.

[gwodus]

This worked for me...
But I needed a pre-fork BTC blockchain...
And ABC would not sync... had to switch to Bitcoin Classic special version.

So (a) any pre-fork chain + (b) any wallet + (c) Bitcoin Classic... wait to sync, enjoy your BCC 

Dang. Is there any way to strip a couple days from the end of the chain? My chain is already post-fork.

[gwodus]

I got it working in Bitcoin ABC as well. The steps I did:

• Run Bitcoin ABC for the first time and stop it again.
• Delete everything in directory Bitcoin\blocks.
• Copy over all the rev*.dat and blk*.dat files from bitcoin core into Bitcoin\blocks (make sure Core is not running).
• Delete all files which have a modification date after 31.07.2017. This is to make sure the chain is in pre-fork condition.
• Now run Bitcoin ABC again. It will start to reindex the blocks. This can take a long time.
• Once the blocks are re-indexed it will connect to the network and catch up with new blocks.

Also, I think it's not a good idea to have Bitcoin Core and Bitcoin ABC running at the same time on the same PC.

The bad news. The hard drive which had enough space for the chain is extremely slow. Re-indexing took me 4! days.

In the mean time I used Coinomi to sweep my forked BCH into it. Worked fast and flawless. I can recommend it.

[firstman]

I got it working in Bitcoin ABC as well. The steps I did:

• Run Bitcoin ABC for the first time and stop it again.
• Delete everything in directory Bitcoin\blocks.
• Copy over all the rev*.dat and blk*.dat files from bitcoin core into Bitcoin\blocks (make sure Core is not running).
• Delete all files which have a modification date after 31.07.2017. This is to make sure the chain is in pre-fork condition.
• Now run Bitcoin ABC again. It will start to reindex the blocks. This can take a long time.
• Once the blocks are re-indexed it will connect to the network and catch up with new blocks.

Also, I think it's not a good idea to have Bitcoin Core and Bitcoin ABC running at the same time on the same PC.

The bad news. The hard drive which had enough space for the chain is extremely slow. Re-indexing took me 4! days.

In the mean time I used Coinomi to sweep my forked BCH into it. Worked fast and flawless. I can recommend it.

Thanks. After moving all the dat files I had to run bitcoin-qt with -reindex otherwise I would get a "Assertion `hashPrevBlock == view.GetBestBlock()' failed. Aborted (core dumped)"