Configuration file when settings are changed in GUI #17692

Hi !

This issue is related to settings that seems to be different when running bitcoind and bitcoin-qt on my laptop.

Thanks for help !

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When settings are changed in bitcoin-qt, no configuration file is created. This has several consequences :

• bitcoind cannot work properly anymore, particulary in the case of a pruned node where it shutdown at start returning You need to rebuild the database using -reindex to go back to unpruned mode. This will redownload the entire blockchain. Please restart with -reindex or -reindex-chainstate to recover.. bitcoin-qt will start normally because it knows that the node is pruned, I have no idea how since it did not write it in any bitcoin.conf (there must be a configuration file somewhere).
• It is hard to review exactly with what settings the node is running if bitcoin-qt has been ran once. In my case, I suspect I have difficulties to run Electrum-Personal-Server (EPS) in multiwallet mode because of some hidden configuration settings (related to the issue https://github.com/chris-belcher/electrum-personal-server/issues/111)

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Ideally, all settings changes made in GUI should be reported directly in configuration file bitcoin.conf but bitcoin-qt could have it's own bitcoin-qt.conf. We just need to make it clear about what are the settings used by qt.

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Settings used for bitcoin-qt must be stored somewhere. I did not find any related configuration file other than bitcoin.conf in datadir and .bitcoin folder. It would be enough to add the location of such file in documentation.

I am on Ubuntu 18.04, I changed the default datadir, it is well detected by bitcoind and bitcoin-qt (and the GUI is opening my own config file correctly when I asked him to open the file). But bitcoind is not working while bitcoin-qt does.

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Here the logs for bitcoind where it shutdowns because of pruning :

2019-12-07T15:32:36Z Bitcoin Core version v0.19.0.1 (release build) 2019-12-07T15:32:36Z Assuming ancestors of block 00000000000000000005f8920febd3925f8272a6a71237563d78c2edfdd09ddf have valid signatures. 2019-12-07T15:32:36Z Setting nMinimumChainWork=000000000000000000000000000000000000000008ea3cf107ae0dec57f03fe8 2019-12-07T15:32:36Z Using the 'sse4(1way),sse41(4way),avx2(8way)' SHA256 implementation 2019-12-07T15:32:36Z Using RdRand as an additional entropy source 2019-12-07T15:32:36Z Default data directory /home/login/.bitcoin 2019-12-07T15:32:36Z Using data directory /home/login/Bitcoin 2019-12-07T15:32:36Z Config file: /home/login/Bitcoin/bitcoin.conf 2019-12-07T15:32:36Z Using at most 125 automatic connections (1024 file descriptors available) 2019-12-07T15:32:36Z Using 16 MiB out of 32/2 requested for signature cache, able to store 524288 elements 2019-12-07T15:32:36Z Using 16 MiB out of 32/2 requested for script execution cache, able to store 524288 elements 2019-12-07T15:32:36Z Using 8 threads for script verification 2019-12-07T15:32:36Z scheduler thread start 2019-12-07T15:32:36Z HTTP: creating work queue of depth 16 2019-12-07T15:32:36Z No rpcpassword set - using random cookie authentication. 2019-12-07T15:32:36Z Generated RPC authentication cookie /home/login/Bitcoin/.cookie 2019-12-07T15:32:36Z HTTP: starting 4 worker threads 2019-12-07T15:32:36Z Using wallet directory /home/login/Bitcoin ... load wallets ... 2019-12-07T15:32:36Z init message: Loading banlist... 2019-12-07T15:32:36Z Cache configuration: 2019-12-07T15:32:36Z * Using 2.0 MiB for block index database 2019-12-07T15:32:36Z * Using 8.0 MiB for chain state database 2019-12-07T15:32:36Z * Using 440.0 MiB for in-memory UTXO set (plus up to 286.1 MiB of unused mempool space) 2019-12-07T15:32:36Z init message: Loading block index... 2019-12-07T15:32:36Z Opening LevelDB in /home/login/Bitcoin/blocks/index 2019-12-07T15:32:36Z Opened LevelDB successfully 2019-12-07T15:32:36Z Using obfuscation key for /home/login/Bitcoin/blocks/index: 0000000000000000 2019-12-07T15:32:39Z LoadBlockIndexDB: last block file = 1888 2019-12-07T15:32:39Z LoadBlockIndexDB: last block file info: CBlockFileInfo(blocks=61, size=60399390, heights=607007...607067, time=2019-12-07...2019-12-07) 2019-12-07T15:32:39Z Checking all blk files are present... 2019-12-07T15:32:39Z LoadBlockIndexDB(): Block files have previously been pruned 2019-12-07T15:32:39Z : You need to rebuild the database using -reindex to go back to unpruned mode. This will redownload the entire blockchain. Please restart with -reindex or -reindex-chainstate to recover. 2019-12-07T15:32:39Z Aborted block database rebuild. Exiting. 2019-12-07T15:32:39Z Shutdown: In progress... 2019-12-07T15:32:39Z scheduler thread interrupt 2019-12-07T15:32:39Z Shutdown: done

bitcoin-qt starts normally with the same configuration :

2019-12-07T15:40:22Z Bitcoin Core version v0.19.0.1 (release build) 2019-12-07T15:40:22Z Assuming ancestors of block 00000000000000000005f8920febd3925f8272a6a71237563d78c2edfdd09ddf have valid signatures. 2019-12-07T15:40:22Z Setting nMinimumChainWork=000000000000000000000000000000000000000008ea3cf107ae0dec57f03fe8 2019-12-07T15:40:22Z Prune configured to target 190734 MiB on disk for block and undo files. 2019-12-07T15:40:22Z Using the 'sse4(1way),sse41(4way),avx2(8way)' SHA256 implementation 2019-12-07T15:40:22Z Using RdRand as an additional entropy source 2019-12-07T15:40:22Z Default data directory /home/login/.bitcoin 2019-12-07T15:40:22Z Using data directory /home/login/Bitcoin 2019-12-07T15:40:22Z Config file: /home/login/Bitcoin/bitcoin.conf 2019-12-07T15:40:22Z Using at most 125 automatic connections (1024 file descriptors available) 2019-12-07T15:40:22Z Using 16 MiB out of 32/2 requested for signature cache, able to store 524288 elements 2019-12-07T15:40:22Z Using 16 MiB out of 32/2 requested for script execution cache, able to store 524288 elements 2019-12-07T15:40:22Z Using 8 threads for script verification 2019-12-07T15:40:22Z scheduler thread start 2019-12-07T15:40:22Z HTTP: creating work queue of depth 16 2019-12-07T15:40:22Z No rpcpassword set - using random cookie authentication. 2019-12-07T15:40:22Z Generated RPC authentication cookie /home/login/Bitcoin/.cookie 2019-12-07T15:40:22Z HTTP: starting 4 worker threads 2019-12-07T15:40:22Z Using wallet directory /home/login/Bitcoin 2019-12-07T15:40:22Z init message: Vérification des porte-monnaie... ... load wallets... 2019-12-07T15:40:22Z init message: Chargement de la liste d’interdiction... 2019-12-07T15:40:22Z Cache configuration: 2019-12-07T15:40:22Z * Using 2.0 MiB for block index database 2019-12-07T15:40:22Z * Using 8.0 MiB for chain state database 2019-12-07T15:40:22Z * Using 3990.0 MiB for in-memory UTXO set (plus up to 286.1 MiB of unused mempool space) 2019-12-07T15:40:22Z init message: Chargement de l’index des blocs… 2019-12-07T15:40:22Z Opening LevelDB in /home/login/Bitcoin/blocks/index 2019-12-07T15:40:22Z Opened LevelDB successfully 2019-12-07T15:40:22Z Using obfuscation key for /home/login/Bitcoin/blocks/index: 0000000000000000 2019-12-07T15:40:25Z LoadBlockIndexDB: last block file = 1888 2019-12-07T15:40:25Z LoadBlockIndexDB: last block file info: CBlockFileInfo(blocks=61, size=60399390, heights=607007...607067, time=2019-12-07...2019-12-07) 2019-12-07T15:40:25Z Checking all blk files are present... 2019-12-07T15:40:25Z LoadBlockIndexDB(): Block files have previously been pruned 2019-12-07T15:40:25Z Opening LevelDB in /home/login/Bitcoin/chainstate 2019-12-07T15:40:25Z Opened LevelDB successfully 2019-12-07T15:40:25Z Using obfuscation key for /home/login/Bitcoin/chainstate: d5826331177f4c85 2019-12-07T15:40:25Z Loaded best chain: hashBestChain=00000000000000000008dc07079dc7649636a1a6e127f422a7b617edc15dfd90 height=607067 date=2019-12-07T15:17:46Z progress=0.999989 2019-12-07T15:40:25Z init message: Rebobinage des blocs... 2019-12-07T15:40:26Z init message: Vérification des blocs... 2019-12-07T15:40:26Z Verifying last 6 blocks at level 3 2019-12-07T15:40:26Z [0%]...[16%]...[33%]...[50%]...[66%]...[83%]...[99%]...[DONE]. 2019-12-07T15:40:28Z No coin database inconsistencies in last 6 blocks (17252 transactions) 2019-12-07T15:40:28Z block index 5561ms 2019-12-07T15:40:28Z init message: Chargement du porte-monnaie…

The config file bitcoin.conf in my datadir /home/login/Bitcoin contains :

server=1 rpcport=8332 disablewallet=0 wallet=Wallet wallet=Wallet2

The config file in /home/login/.bitcoin contains only datadir=/home/login/Bitcoin This shows that bitcoin-qt did not report that it has pruned the node, although it knows it.

See #15936

Nice ! I didn't saw this PR, thank you for pointing it. It seems that the hidden settings I talk about are somewhere in Qt files then.

More details on the configuration file's location on this website : https://dev-notes.eu/2018/04/amend-bitcoin-qt-persistent-settings-for-bitcoin-core/

TLDR :

Location of Config File: Linux On Linux/Unix systems, the following files are used by default:

$HOME/.config/Bitcoin/Bitcoin-Qt.conf $HOME/.config/Bitcoin-Qt.conf For myself, running Bitcoin Core under Ubuntu 16.04 the config file is $HOME/.config/Bitcoin/Bitcoin-Qt.conf

Location of Config File: Mac OS On Mac OS X check the following locations:

$HOME/Library/Preferences/com.Bitcoin $HOME/Library/Preferences/com.Bitcoin /Library/Preferences/com.Bitcoin /Library/Preferences/com.Bitcoin Location of Config File: Windows On Windows, check the following registry paths:

HKEY_CURRENT_USER\Software\Bitcoin HKEY_CURRENT_USER\Software\Bitcoin HKEY_LOCAL_MACHINE\Software\Bitcoin HKEY_LOCAL_MACHINE\Software\Bitcoin