MultiChain Developer Q&A - Recent questions tagged datadir

multichain-util clone is ignoring -datadir option

Wed, 08 Nov 2023 14:05:35 +0000

After creating a chain like so:

multichain-util create test-test_3 -datadir=/mnt/disks/data/multichain_data/
MultiChain 2.3 Utilities (latest protocol 20013)
Blockchain parameter set was successfully generated.
You can edit it in /mnt/disks/data/multichain_data/test-test_3/params.dat before running multichaind for the first time.
To generate blockchain please run "multichaind test-test_3 -daemon".
Cannot create chain parameter set, file /home/test/.multichain/public_access_3/params.dat does not exist

I start the chain

multichaind test-test_3 -daemon
MultiChain 2.3 Daemon (Community Edition, latest protocol 20013)
Starting up node...
ERROR: Parameter set for blockchain test-test_3 is not complete.

If you want to create new blockchain please run one of the following:
multichain-util create test-test_3
multichain-util clone <old-blockchain-name> test-test_3
And rerun multichaind test-test_3

If you want to connect to existing blockchain please specify seed node:
multichaind test-test_3@<seed-node-ip>
multichaind test-test_3@<seed-node-ip>:<seed-node-port>

And when I try to clone an existing chain, -datadir is ignored and instead the multichain-util thinks I am pointing to elsewhere.

multichain-util clone public_access_3 test-test_3 -datadir=/mnt/disks/data/multichain_data/
MultiChain 2.3 Utilities (latest protocol 20013)
Cannot create chain parameter set, file /home/test/.multichain/public_access_3/params.dat does not exist
ERROR: Blockchain parameter set was not generated.

Use persistent data dir as failover mechanism

Fri, 18 Jan 2019 18:52:02 +0000

Hi,

I'm running Multichain as master in a docker container with a volume mapped to a permanent storage so if the container dies, it can be restarted using the same data dir.

However this is not working as expected, as on restart, I get the following error:

/data/chain1 folder already exists...
Starting the chain with multichaind -txindex -printtoconsole -shrinkdebugfilesize -datadir=/data chain1...
MultiChain 2.0 beta 1 Daemon (latest protocol 20006)

MultiChain version build 2.0 beta 1 protocol 20006 (Nov 21 2018, 10:39:54)
Using OpenSSL version OpenSSL 1.0.1h 5 Jun 2014
Using BerkeleyDB version Berkeley DB 4.8.30: (April 9, 2010)
Default data directory /data/chain1
Using data directory /data/chain1
Using config file /data/chain1/chain1.conf
Using at most 125 connections (65536 file descriptors available)
Using 16 threads for script verification
Using wallet wallet.dat
init message: Verifying wallet...
CDBEnv::Open : LogDir=/data/chain1/database ErrorFile=/data/chain1/db.log
init message: Initializing multichain...
mchn: Parameter set is valid - initializing blockchain parameters...
Wallet mode: 00000003
nFileVersion = 100000
Keys: 2 plaintext, 0 encrypted, 2 w/ metadata, 2 total
Node paused state is set to 00000000
Binding RPC on address :: port 8570 (IPv4+IPv6 bind any: 1)
Bound to [::]:8571
Bound to 0.0.0.0:8571
Filter initialization completed
Other nodes can connect to this node using:
multichaind chain1@174.16.212.240:8571
Setting banned transaction list: 0 transactions
init message: Loading block index...
Opening LevelDB in /data/chain1/blocks/index
Opened LevelDB successfully
Opening LevelDB in /data/chain1/chainstate
Opened LevelDB successfully
nFileVersion = 100000
Keys: 2 plaintext, 0 encrypted, 2 w/ metadata, 2 total
LoadBlockIndexDB: last block file = 0
LoadBlockIndexDB: last block file info: CBlockFileInfo(blocks=11, size=3000, heights=0...10, time=2019-01-18...2019-01-18)
Checking all blk files are present...
LoadBlockIndexDB(): transaction index enabled
LoadBlockIndexDB(): hashBestChain=006e9bbff1dd146a9cdff73d4bd8e1f729f4f75568650f0523f3e0b99e345229 height=10 date=2019-01-18 18:08:26 progress=1.000000
Error: Incorrect or no genesis block found. Wrong datadir for network?
Error: Incorrect or no genesis block found. Wrong datadir for network?
Shutdown: In progress...
StopNode()
Node stopped
Shutdown: done
CDBEnv::EnvShutdown : Error 22 shutting down database environment: Invalid argument

Apparently, on restart, it's detecting that there is already an existing data dir, so it's just trying to spin up the master node again using it with:

multichaind -txindex -printtoconsole -shrinkdebugfilesize -datadir=/data chain1

But maybe I need to start it in a different way when the data dir is already there.

Can you please advice?

Thanks!

Why does using multichain-cli on the node thats running require datadir?

Tue, 01 Aug 2017 08:46:28 +0000

It seems a little strange that the multichain-cli cannot find the datadir or that it even requires the datadir for that matter.

Surely the node should know its own directory and not rely on cli passing this through?

Bug in Multichain-cli for datadir option?

Tue, 01 Aug 2017 08:32:04 +0000

I am granting a node after bringing up a new chain on our test server. We are using the -datadir=b:\

I am getting error: Error parsing JSON:-datadir=b:\

multichain-util and multichaind both accepted b:\ drive letter

Can I use any folder with the datadir parameter?

Thu, 26 Jan 2017 20:59:25 +0000

Can I use any folder with the datadir parameter? Specifically "c:\MULTICHAIN\node0\chains\chain0\" The reason I am asking is that when I try to run the chain with the multichaind in this case, it says "ERROR: Parameter set for blockchain chain0 is not complete."
Do I always have to use %AppData%... ?

And actually, what I want to achieve first of all is to run multiple nodes on one PS. How do I do this?

Thanks.