Error opening block database

Question

Hi,

I was suddenly not able to start my chain and faced with the following error... I was working with this chain till recently. I have tried to restart the chain with reindex=1 many times.. I would like to know whether we have any other tools and ways to try to bring this chain up.. .

multichaind test3@10.10.10.1:7433

: Error opening block database.

Please restart multichaind with reindex=1.

Thanks, Saravana

Answer 1

First please make sure you are using the latest version of MultiChain. Some beta 1 MultiChain has implemented more thorough recovery of corrupt data.

If this does not help we would like to review your files to understand what happened. If you are willing please zip up your blockchain folder and send it to multichain dot debug at gmail dot com.

Answer 2

Thanks for sending over the files - we took a look.

First the cause appears to be that multichaind was terminated with no warning, perhaps by a Windows reboot, and this happened to interrupt a disk write operation that left the files in an inconsistent state. We've thoroughly tested that this does not happen with a hard termination on Linux, but it's possible that under Windows the underlying file system's characteristics are different and less hardy. Does this cause make sense?

Second we checked the logs and it appears you didn't yet try reindexing. Did you run multichaind with the -reindex=1 command line parameter and wait for it to finish? We can't see any sign of that in the logs.

Comments

Thanks, I would have pressed Cntl+C for closing the node..
I am open to bring this up with -reindex=1 but it's more than an hour now, the node is up and running and I am not seeing some of the streams yet.. Hoping that it's still recovering or trying to recover.

Is there any way to check the progress of recover or reindex?

Thanks.

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You can watch the block count in getinfo or getblockchaininfo to see which block has been reached so far in the reindexing. Or look in debug.log for more details.