Copying instead of downloading the blockchain

RangerK

member

Activity: 93

Merit: 10

Quote from: juhakall on June 26, 2013, 06:17:14 AM

I copied all my *coin blockchains from Debian Linux to FreeBSD. All clients were properly shut down on Linux. None of the newly compiled clients would work on FreeBSD because of database errors, until I removed the copied blockchains and started from scratch. Should the blockchain files be transferable between different operating systems? Can anyone explain why I had to do this?

Interestingly, I also tried a move between operating systems. (Windows XP -> Xubuntu). Haven't experimented copies within the same OS.

kjj

legendary

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Quote from: juhakall on June 26, 2013, 06:17:14 AM

I transferred all my *coin clients, including their databases, from Debian Linux to FreeBSD. They were all properly shut down. None of them would work until I removed the databases and started from scratch. Should the database files be transferable between different operating systems?

I have no idea. It would depend on how the database library is written. The blockchain files themselves are platform-agnostic: values are written in a screwy byte order and each client is responsible for converting that order to their internal format.

If I had to guess, I'd expect the database files to be similar, and thus be compatible between operating systems, and maybe even between CPUs. But I don't really know.

When you say they were shut down properly, do you mean the databases were detached too? Do the altcoins even support that correctly?

juhakall

sr. member

Activity: 658

Merit: 250

I copied all my *coin blockchains from Debian Linux to FreeBSD. All clients were properly shut down on Linux. None of the newly compiled clients would work on FreeBSD because of database errors, until I removed the copied blockchains and started from scratch. Should the blockchain files be transferable between different operating systems? Can anyone explain why I had to do this?

kjj

legendary

Activity: 1302

Merit: 1026

It is possible to copy the blockchain around. At least it was pre-0.8. I don't see any reason why you wouldn't be able to after leveldb, I just haven't tried it yet.

You just need to make sure that you get the entire chain and index in one shot. In the BDB days, that meant doing a shutdown-with-detach, then copying all of the block files with the index.

bit_kevin

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Activity: 64

Merit: 10

btc.com

You can use bootstrap.dat when first start an bitcoind.

FYI:
https://bitcointalksearch.org/topic/beta-bitcoin-blockchain-torrent-117982
http://eu2.bitcoincharts.com/blockchain/

RangerK

member

Activity: 93

Merit: 10

In the interested of saving time, I tried this recently (on Ubuntu 12.04) and the qt client kept hanging without ever opening. Am I correct to assume that the blockchain can only be downloaded, not copied?

Topic: Copying instead of downloading the blockchain (Read 750 times)