IO error: /home/ubuntu/.multichain/chain/permissions.db/MANIFEST-000002: No such file or directory

Question

I've been running a private blockchain for a couple of weeks now and suddenly I encountered this error today while running multichaind chain -daemon

MultiChain Core Daemon build 1.0 alpha 27 protocol 10007

 

MultiChain server starting

IO error: /home/ubuntu/.multichain/chain/permissions.db/MANIFEST-000002: No such file or directory

 

ERROR: Couldn't initialize permission database for blockchain chain. Probably multichaind for this blockchain is already running. Exiting...

I was able to resolve this by running multichaind chain -reindex. However, I want to investigate what happened or what caused my chain to fail like this so it won't happen again. What files can I look into to determine what happened?

Thanks!

Answer 1

The most likely explanation is that another copy of MultiChain was already running on the same blockchain, as stated in the error message. Are you sure this wasn't the case?

Also note you should be using the latest release version at this point, not such an old alpha :)

Comments

I ran ps -x | grep multichain and found no other running instances. Any other possible cause? And yeah, I should update it already :) Thanks!

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We did a lot of work for alpha 29 to prevent data corruption issues if the node was stopped unexpectedly, so this problem is probably resolved. But if it happens again please create a copy of the blockchain directory before reindexing so that we can examine what happened.