Ncp-baclup doesn't work

Support intro

Sorry to hear you’re facing problems :slightly_frowning_face:

help.nextcloud.com is for home/non-enterprise users. If you’re running a business, paid support can be accessed via portal.nextcloud.com where we can ensure your business keeps running smoothly.

Nextcloud version (eg, 20.0.5): 2.0.11
Operating system and version (eg, Ubuntu 20.04): raspbian 10
Apache or nginx version (eg, Apache 2.4.25): apache 2.4.38
PHP version (eg, 7.4): 7.3.31

The issue you are facing:
cannot get the backup script to work.
wherever it is ran it returns:

Running nc-backup
Error reading data directory. Is NextCloud running and configured?
Done. Press any key...

nextcloud works fine, so it isn’t related to the whole server.
I’ve tried running the command to get the data path manually and got:

sudo -u www-data php  occ config:system:get datadirectory
An unhandled exception has been thrown:
ArgumentCountError: Too few arguments to function OCA\PreviewGenerator\Command\Generate::__construct(), 0 passed in /var/www/nextcloud/lib/private/Console/Application.php on line 224 and at least 5 expected in /var/www/nextcloud/apps/previewgenerator/lib/Command/Generate.php:72
Stack trace:
#0 /var/www/nextcloud/lib/private/Console/Application.php(224): OCA\PreviewGenerator\Command\Generate->__construct()
#1 /var/www/nextcloud/lib/private/Console/Application.php(136): OC\Console\Application->loadCommandsFromInfoXml(Array)
#2 /var/www/nextcloud/console.php(99): OC\Console\Application->loadCommands(Object(Symfony\Component\Console\Input\ArgvInput), Object(Symfony\Component\Console\Output\ConsoleOutput))
#3 /var/www/nextcloud/occ(11): require_once('/var/www/nextcl...')

I noticed the presence of previewgenerator, so I tried running it with the usual path (it used to work) and got:

Running nc-previews
An unhandled exception has been thrown:
ArgumentCountError: Too few arguments to function OCA\PreviewGenerator\Command\Generate::__construct(), 0 passed in /var/www/nextcloud/lib/private/Console/Application.php on line 224 and at least 5 expected in /var/www/nextcloud/apps/previewgenerator/lib/Command/Generate.php:72
Stack trace:
#0 /var/www/nextcloud/lib/private/Console/Application.php(224): OCA\PreviewGenerator\Command\Generate->__construct()
#1 /var/www/nextcloud/lib/private/Console/Application.php(136): OC\Console\Application->loadCommandsFromInfoXml(Array)
#2 /var/www/nextcloud/console.php(99): OC\Console\Application->loadCommands(Object(Symfony\Component\Console\Input\ArgvInput), Object(Symfony\Component\Console\Output\ConsoleOutput))
#3 /var/www/nextcloud/occ(11): require_once('/var/www/nextcl...')
#4 {main}An unhandled exception has been thrown:
ArgumentCountError: Too few arguments to function OCA\PreviewGenerator\Command\Generate::__construct(), 0 passed in /var/www/nextcloud/lib/private/Console/Application.php on line 224 and at least 5 expected in /var/www/nextcloud/apps/previewgenerator/lib/Command/Generate.php:72
Stack trace:
#0 /var/www/nextcloud/lib/private/Console/Application.php(224): OCA\PreviewGenerator\Command\Generate->__construct()
#1 /var/www/nextcloud/lib/private/Console/Application.php(136): OC\Console\Application->loadCommandsFromInfoXml(Array)
#2 /var/www/nextcloud/console.php(99): OC\Console\Application->loadCommands(Object(Symfony\Component\Console\Input\ArgvInput), Object(Symfony\Component\Console\Output\ConsoleOutput))
#3 /var/www/nextcloud/occ(11): require_once('/var/www/nextcl...')
#4 {main}An unhandled exception has been thrown:
ArgumentCountError: Too few arguments to function OCA\PreviewGenerator\Command\Generate::__construct(), 0 passed in /var/www/nextcloud/lib/private/Console/Application.php on line 224 and at least 5 expected in /var/www/nextcloud/apps/previewgenerator/lib/Command/Generate.php:72
Stack trace:
#0 /var/www/nextcloud/lib/private/Console/Application.php(224): OCA\PreviewGenerator\Command\Generate->__construct()
#1 /var/www/nextcloud/lib/private/Console/Application.php(136): OC\Console\Application->loadCommandsFromInfoXml(Array)
#2 /var/www/nextcloud/console.php(99): OC\Console\Application->loadCommands(Object(Symfony\Component\Console\Input\ArgvInput), Object(Symfony\Component\Console\Output\ConsoleOutput))
#3 /var/www/nextcloud/occ(11): require_once('/var/www/nextcl...')
#4 {main}An unhandled exception has been thrown:
ArgumentCountError: Too few arguments to function OCA\PreviewGenerator\Command\Generate::__construct(), 0 passed in /var/www/nextcloud/lib/private/Console/Application.php on line 224 and at least 5 expected in /var/www/nextcloud/apps/previewgenerator/lib/Command/Generate.php:72
Stack trace:
#0 /var/www/nextcloud/lib/private/Console/Application.php(224): OCA\PreviewGenerator\Command\Generate->__construct()
#1 /var/www/nextcloud/lib/private/Console/Application.php(136): OC\Console\Application->loadCommandsFromInfoXml(Array)
#2 /var/www/nextcloud/console.php(99): OC\Console\Application->loadCommands(Object(Symfony\Component\Console\Input\ArgvInput), Object(Symfony\Component\Console\Output\ConsoleOutput))
#3 /var/www/nextcloud/occ(11): require_once('/var/www/nextcl...')
#4 {main}Done. Press any key...

Is this the first time you’ve seen this error? (Y/N): Y

Steps to replicate it:

  1. try running ncp-backup in webui or ncp-config
  2. watch fail

The output of your Nextcloud log in Admin > Logging:

[ nc-previews-auto ]
An unhandled exception has been thrown:
Doctrine\DBAL\DBALException: Failed to connect to the database: An exception occurred in driver: SQLSTATE[HY000] [2002] No such file or directory in /var/www/nextcloud/lib/private/DB/Connection.php:72
Stack trace:
#0 /var/www/nextcloud/3rdparty/doctrine/dbal/lib/Doctrine/DBAL/Connection.php(1449): OC\DB\Connection->connect()
#1 /var/www/nextcloud/3rdparty/doctrine/dbal/lib/Doctrine/DBAL/Connection.php(892): Doctrine\DBAL\Connection->getWrappedConnection()
#2 /var/www/nextcloud/lib/private/DB/Connection.php(202): Doctrine\DBAL\Connection->executeQuery('SELECT * FROM `...', Array, Array, NULL)
#3 /var/www/nextcloud/3rdparty/doctrine/dbal/lib/Doctrine/DBAL/Query/QueryBuilder.php(206): OC\DB\Connection->executeQuery('SELECT * FROM `...', Array, Array)
#4 /var/www/nextcloud/lib/private/DB/QueryBuilder/QueryBuilder.php(248): Doctrine\DBAL\Query\QueryBuilder->execute()
#5 /var/www/nextcloud/lib/private/AppConfig.php(345): OC\DB\QueryBuilder\QueryBuilder->execute()
#6 /var/www/nextcloud/lib/private/AppConfig.php(110): OC\AppConfig->loadConfigValues()
#7 /var/www/nextcloud/lib/private/AppConfig.php(301): OC\AppConfig->getApps()
#8 /var/www/nextcloud/lib/private/legacy/OC_App.php(957): OC\AppConfig->getValues(false, 'installed_versi...')
#9 /var/www/nextcloud/lib/private/Server.php(668): OC_App::getAppVersions()
#10 /var/www/nextcloud/lib/private/AppFramework/Utility/SimpleContainer.php(155): OC\Server->OC\{closure}(Object(OC\Server))
#11 /var/www/nextcloud/3rdparty/pimple/pimple/src/Pimple/Container.php(118): OC\AppFramework\Utility\SimpleContainer->OC\AppFramework\Utility\{closure}(Object(Pimple\Container))
#12 /var/www/nextcloud/lib/private/AppFramework/Utility/SimpleContainer.php(122): Pimple\Container->offsetGet('OC\\Memcache\\Fac...')
#13 /var/www/nextcloud/lib/private/ServerContainer.php(156): OC\AppFramework\Utility\SimpleContainer->query('OC\\Memcache\\Fac...', true)
#14 /var/www/nextcloud/lib/private/Server.php(1677): OC\ServerContainer->query('OC\\Memcache\\Fac...')
#15 /var/www/nextcloud/lib/private/Server.php(1017): OC\Server->getMemCacheFactory()
#16 /var/www/nextcloud/lib/private/AppFramework/Utility/SimpleContainer.php(155): OC\Server->OC\{closure}(Object(OC\Server))
#17 /var/www/nextcloud/3rdparty/pimple/pimple/src/Pimple/Container.php(118): OC\AppFramework\Utility\SimpleContainer->OC\AppFramework\Utility\{closure}(Object(Pimple\Container))
#18 /var/www/nextcloud/lib/private/AppFramework/Utility/SimpleContainer.php(122): Pimple\Container->offsetGet('OCP\\Lock\\ILocki...')
#19 /var/www/nextcloud/lib/private/ServerContainer.php(156): OC\AppFramework\Utility\SimpleContainer->query('OCP\\Lock\\ILocki...', true)
#20 /var/www/nextcloud/lib/private/Server.php(1977): OC\ServerContainer->query('OCP\\Lock\\ILocki...')
#21 /var/www/nextcloud/lib/private/Files/View.php(118): OC\Server->getLockingProvider()
#22 /var/www/nextcloud/lib/private/Server.php(395): OC\Files\View->__construct()
#23 /var/www/nextcloud/lib/private/AppFramework/Utility/SimpleContainer.php(155): OC\Server->OC\{closure}(Object(OC\Server))
#24 /var/www/nextcloud/3rdparty/pimple/pimple/src/Pimple/Container.php(118): OC\AppFramework\Utility\SimpleContainer->OC\AppFramework\Utility\{closure}(Object(Pimple\Container))
#25 /var/www/nextcloud/lib/private/AppFramework/Utility/SimpleContainer.php(122): Pimple\Container->offsetGet('OC\\Files\\Node\\H...')
#26 /var/www/nextcloud/lib/private/ServerContainer.php(156): OC\AppFramework\Utility\SimpleContainer->query('OC\\Files\\Node\\H...', true)
#27 /var/www/nextcloud/lib/private/Server.php(1324): OC\ServerContainer->query('OC\\Files\\Node\\H...')
#28 /var/www/nextcloud/lib/base.php(595): OC\Server->boot()
#29 /var/www/nextcloud/lib/base.php(1091): OC::init()
#30 /var/www/nextcloud/console.php(49): require_once('/var/www/nextcl...')
#31 /var/www/nextcloud/occ(11): require_once('/var/www/nextcl...')
#32 {main}An unhandled exception has been thrown:
Doctrine\DBAL\DBALException: Failed to connect to the database: An exception occurred in driver: SQLSTATE[HY000] [2002] No such file or directory in /var/www/nextcloud/lib/private/DB/Connection.php:72
Stack trace:
#0 /var/www/nextcloud/3rdparty/doctrine/dbal/lib/Doctrine/DBAL/Connection.php(1449): OC\DB\Connection->connect()
#1 /var/www/nextcloud/3rdparty/doctrine/dbal/lib/Doctrine/DBAL/Connection.php(892): Doctrine\DBAL\Connection->getWrappedConnection()
#2 /var/www/nextcloud/lib/private/DB/Connection.php(202): Doctrine\DBAL\Connection->executeQuery('SELECT * FROM `...', Array, Array, NULL)
#3 /var/www/nextcloud/3rdparty/doctrine/dbal/lib/Doctrine/DBAL/Query/QueryBuilder.php(206): OC\DB\Connection->executeQuery('SELECT * FROM `...', Array, Array)
#4 /var/www/nextcloud/lib/private/DB/QueryBuilder/QueryBuilder.php(248): Doctrine\DBAL\Query\QueryBuilder->execute()
#5 /var/www/nextcloud/lib/private/AppConfig.php(345): OC\DB\QueryBuilder\QueryBuilder->execute()
#6 /var/www/nextcloud/lib/private/AppConfig.php(110): OC\AppConfig->loadConfigValues()
#7 /var/www/nextcloud/lib/private/AppConfig.php(301): OC\AppConfig->getApps()
#8 /var/www/nextcloud/lib/private/legacy/OC_App.php(957): OC\AppConfig->getValues(false, 'installed_versi...')
#9 /var/www/nextcloud/lib/private/Server.php(668): OC_App::getAppVersions()
#10 /var/www/nextcloud/lib/private/AppFramework/Utility/SimpleContainer.php(155): OC\Server->OC\{closure}(Object(OC\Server))
#11 /var/www/nextcloud/3rdparty/pimple/pimple/src/Pimple/Container.php(118): OC\AppFramework\Utility\SimpleContainer->OC\AppFramework\Utility\{closure}(Object(Pimple\Container))
#12 /var/www/nextcloud/lib/private/AppFramework/Utility/SimpleContainer.php(122): Pimple\Container->offsetGet('OC\\Memcache\\Fac...')
#13 /var/www/nextcloud/lib/private/ServerContainer.php(156): OC\AppFramework\Utility\SimpleContainer->query('OC\\Memcache\\Fac...', true)
#14 /var/www/nextcloud/lib/private/Server.php(1677): OC\ServerContainer->query('OC\\Memcache\\Fac...')
#15 /var/www/nextcloud/lib/private/Server.php(1017): OC\Server->getMemCacheFactory()
#16 /var/www/nextcloud/lib/private/AppFramework/Utility/SimpleContainer.php(155): OC\Server->OC\{closure}(Object(OC\Server))
#17 /var/www/nextcloud/3rdparty/pimple/pimple/src/Pimple/Container.php(118): OC\AppFramework\Utility\SimpleContainer->OC\AppFramework\Utility\{closure}(Object(Pimple\Container))
#18 /var/www/nextcloud/lib/private/AppFramework/Utility/SimpleContainer.php(122): Pimple\Container->offsetGet('OCP\\Lock\\ILocki...')
#19 /var/www/nextcloud/lib/private/ServerContainer.php(156): OC\AppFramework\Utility\SimpleContainer->query('OCP\\Lock\\ILocki...', true)
#20 /var/www/nextcloud/lib/private/Server.php(1977): OC\ServerContainer->query('OCP\\Lock\\ILocki...')
#21 /var/www/nextcloud/lib/private/Files/View.php(118): OC\Server->getLockingProvider()
#22 /var/www/nextcloud/lib/private/Server.php(395): OC\Files\View->__construct()
#23 /var/www/nextcloud/lib/private/AppFramework/Utility/SimpleContainer.php(155): OC\Server->OC\{closure}(Object(OC\Server))
#24 /var/www/nextcloud/3rdparty/pimple/pimple/src/Pimple/Container.php(118): OC\AppFramework\Utility\SimpleContainer->OC\AppFramework\Utility\{closure}(Object(Pimple\Container))
#25 /var/www/nextcloud/lib/private/AppFramework/Utility/SimpleContainer.php(122): Pimple\Container->offsetGet('OC\\Files\\Node\\H...')
#26 /var/www/nextcloud/lib/private/ServerContainer.php(156): OC\AppFramework\Utility\SimpleContainer->query('OC\\Files\\Node\\H...', true)
#27 /var/www/nextcloud/lib/private/Server.php(1324): OC\ServerContainer->query('OC\\Files\\Node\\H...')
#28 /var/www/nextcloud/lib/base.php(595): OC\Server->boot()
#29 /var/www/nextcloud/lib/base.php(1091): OC::init()
#30 /var/www/nextcloud/console.php(49): require_once('/var/www/nextcl...')
#31 /var/www/nextcloud/occ(11): require_once('/var/www/nextcl...')
#32 {main}An unhandled exception has been thrown:
Doctrine\DBAL\DBALException: Failed to connect to the database: An exception occurred in driver: SQLSTATE[HY000] [2002] No such file or directory in /var/www/nextcloud/lib/private/DB/Connection.php:72
Stack trace:
#0 /var/www/nextcloud/3rdparty/doctrine/dbal/lib/Doctrine/DBAL/Connection.php(1449): OC\DB\Connection->connect()
#1 /var/www/nextcloud/3rdparty/doctrine/dbal/lib/Doctrine/DBAL/Connection.php(892): Doctrine\DBAL\Connection->getWrappedConnection()
#2 /var/www/nextcloud/lib/private/DB/Connection.php(202): Doctrine\DBAL\Connection->executeQuery('SELECT * FROM `...', Array, Array, NULL)
#3 /var/www/nextcloud/3rdparty/doctrine/dbal/lib/Doctrine/DBAL/Query/QueryBuilder.php(206): OC\DB\Connection->executeQuery('SELECT * FROM `...', Array, Array)
#4 /var/www/nextcloud/lib/private/DB/QueryBuilder/QueryBuilder.php(248): Doctrine\DBAL\Query\QueryBuilder->execute()
#5 /var/www/nextcloud/lib/private/AppConfig.php(345): OC\DB\QueryBuilder\QueryBuilder->execute()
#6 /var/www/nextcloud/lib/private/AppConfig.php(110): OC\AppConfig->loadConfigValues()
#7 /var/www/nextcloud/lib/private/AppConfig.php(301): OC\AppConfig->getApps()
#8 /var/www/nextcloud/lib/private/legacy/OC_App.php(957): OC\AppConfig->getValues(false, 'installed_versi...')
#9 /var/www/nextcloud/lib/private/Server.php(668): OC_App::getAppVersions()
#10 /var/www/nextcloud/lib/private/AppFramework/Utility/SimpleContainer.php(155): OC\Server->OC\{closure}(Object(OC\Server))
#11 /var/www/nextcloud/3rdparty/pimple/pimple/src/Pimple/Container.php(118): OC\AppFramework\Utility\SimpleContainer->OC\AppFramework\Utility\{closure}(Object(Pimple\Container))
#12 /var/www/nextcloud/lib/private/AppFramework/Utility/SimpleContainer.php(122): Pimple\Container->offsetGet('OC\\Memcache\\Fac...')
#13 /var/www/nextcloud/lib/private/ServerContainer.php(156): OC\AppFramework\Utility\SimpleContainer->query('OC\\Memcache\\Fac...', true)
#14 /var/www/nextcloud/lib/private/Server.php(1677): OC\ServerContainer->query('OC\\Memcache\\Fac...')
#15 /var/www/nextcloud/lib/private/Server.php(1017): OC\Server->getMemCacheFactory()
#16 /var/www/nextcloud/lib/private/AppFramework/Utility/SimpleContainer.php(155): OC\Server->OC\{closure}(Object(OC\Server))
#17 /var/www/nextcloud/3rdparty/pimple/pimple/src/Pimple/Container.php(118): OC\AppFramework\Utility\SimpleContainer->OC\AppFramework\Utility\{closure}(Object(Pimple\Container))
#18 /var/www/nextcloud/lib/private/AppFramework/Utility/SimpleContainer.php(122): Pimple\Container->offsetGet('OCP\\Lock\\ILocki...')
#19 /var/www/nextcloud/lib/private/ServerContainer.php(156): OC\AppFramework\Utility\SimpleContainer->query('OCP\\Lock\\ILocki...', true)
#20 /var/www/nextcloud/lib/private/Server.php(1977): OC\ServerContainer->query('OCP\\Lock\\ILocki...')
#21 /var/www/nextcloud/lib/private/Files/View.php(118): OC\Server->getLockingProvider()
#22 /var/www/nextcloud/lib/private/Server.php(395): OC\Files\View->__construct()
#23 /var/www/nextcloud/lib/private/AppFramework/Utility/SimpleContainer.php(155): OC\Server->OC\{closure}(Object(OC\Server))
#24 /var/www/nextcloud/3rdparty/pimple/pimple/src/Pimple/Container.php(118): OC\AppFramework\Utility\SimpleContainer->OC\AppFramework\Utility\{closure}(Object(Pimple\Container))
#25 /var/www/nextcloud/lib/private/AppFramework/Utility/SimpleContainer.php(122): Pimple\Container->offsetGet('OC\\Files\\Node\\H...')
#26 /var/www/nextcloud/lib/private/ServerContainer.php(156): OC\AppFramework\Utility\SimpleContainer->query('OC\\Files\\Node\\H...', true)
#27 /var/www/nextcloud/lib/private/Server.php(1324): OC\ServerContainer->query('OC\\Files\\Node\\H...')
#28 /var/www/nextcloud/lib/base.php(595): OC\Server->boot()
#29 /var/www/nextcloud/lib/base.php(1091): OC::init()
#30 /var/www/nextcloud/console.php(49): require_once('/var/www/nextcl...')
#31 /var/www/nextcloud/occ(11): require_once('/var/www/nextcl...')
#32 {main}An unhandled exception has been thrown:
Doctrine\DBAL\DBALException: Failed to connect to the database: An exception occurred in driver: SQLSTATE[HY000] [2002] No such file or directory in /var/www/nextcloud/lib/private/DB/Connection.php:72
Stack trace:
#0 /var/www/nextcloud/3rdparty/doctrine/dbal/lib/Doctrine/DBAL/Connection.php(1449): OC\DB\Connection->connect()
#1 /var/www/nextcloud/3rdparty/doctrine/dbal/lib/Doctrine/DBAL/Connection.php(892): Doctrine\DBAL\Connection->getWrappedConnection()
#2 /var/www/nextcloud/lib/private/DB/Connection.php(202): Doctrine\DBAL\Connection->executeQuery('SELECT * FROM `...', Array, Array, NULL)
#3 /var/www/nextcloud/3rdparty/doctrine/dbal/lib/Doctrine/DBAL/Query/QueryBuilder.php(206): OC\DB\Connection->executeQuery('SELECT * FROM `...', Array, Array)
#4 /var/www/nextcloud/lib/private/DB/QueryBuilder/QueryBuilder.php(248): Doctrine\DBAL\Query\QueryBuilder->execute()
#5 /var/www/nextcloud/lib/private/AppConfig.php(345): OC\DB\QueryBuilder\QueryBuilder->execute()
#6 /var/www/nextcloud/lib/private/AppConfig.php(110): OC\AppConfig->loadConfigValues()
#7 /var/www/nextcloud/lib/private/AppConfig.php(301): OC\AppConfig->getApps()
#8 /var/www/nextcloud/lib/private/legacy/OC_App.php(957): OC\AppConfig->getValues(false, 'installed_versi...')
#9 /var/www/nextcloud/lib/private/Server.php(668): OC_App::getAppVersions()
#10 /var/www/nextcloud/lib/private/AppFramework/Utility/SimpleContainer.php(155): OC\Server->OC\{closure}(Object(OC\Server))
#11 /var/www/nextcloud/3rdparty/pimple/pimple/src/Pimple/Container.php(118): OC\AppFramework\Utility\SimpleContainer->OC\AppFramework\Utility\{closure}(Object(Pimple\Container))
#12 /var/www/nextcloud/lib/private/AppFramework/Utility/SimpleContainer.php(122): Pimple\Container->offsetGet('OC\\Memcache\\Fac...')
#13 /var/www/nextcloud/lib/private/ServerContainer.php(156): OC\AppFramework\Utility\SimpleContainer->query('OC\\Memcache\\Fac...', true)
#14 /var/www/nextcloud/lib/private/Server.php(1677): OC\ServerContainer->query('OC\\Memcache\\Fac...')
#15 /var/www/nextcloud/lib/private/Server.php(1017): OC\Server->getMemCacheFactory()
#16 /var/www/nextcloud/lib/private/AppFramework/Utility/SimpleContainer.php(155): OC\Server->OC\{closure}(Object(OC\Server))
#17 /var/www/nextcloud/3rdparty/pimple/pimple/src/Pimple/Container.php(118): OC\AppFramework\Utility\SimpleContainer->OC\AppFramework\Utility\{closure}(Object(Pimple\Container))
#18 /var/www/nextcloud/lib/private/AppFramework/Utility/SimpleContainer.php(122): Pimple\Container->offsetGet('OCP\\Lock\\ILocki...')
#19 /var/www/nextcloud/lib/private/ServerContainer.php(156): OC\AppFramework\Utility\SimpleContainer->query('OCP\\Lock\\ILocki...', true)
#20 /var/www/nextcloud/lib/private/Server.php(1977): OC\ServerContainer->query('OCP\\Lock\\ILocki...')
#21 /var/www/nextcloud/lib/private/Files/View.php(118): OC\Server->getLockingProvider()
#22 /var/www/nextcloud/lib/private/Server.php(395): OC\Files\View->__construct()
#23 /var/www/nextcloud/lib/private/AppFramework/Utility/SimpleContainer.php(155): OC\Server->OC\{closure}(Object(OC\Server))
#24 /var/www/nextcloud/3rdparty/pimple/pimple/src/Pimple/Container.php(118): OC\AppFramework\Utility\SimpleContainer->OC\AppFramework\Utility\{closure}(Object(Pimple\Container))
#25 /var/www/nextcloud/lib/private/AppFramework/Utility/SimpleContainer.php(122): Pimple\Container->offsetGet('OC\\Files\\Node\\H...')
#26 /var/www/nextcloud/lib/private/ServerContainer.php(156): OC\AppFramework\Utility\SimpleContainer->query('OC\\Files\\Node\\H...', true)
#27 /var/www/nextcloud/lib/private/Server.php(1324): OC\ServerContainer->query('OC\\Files\\Node\\H...')
#28 /var/www/nextcloud/lib/base.php(595): OC\Server->boot()
#29 /var/www/nextcloud/lib/base.php(1091): OC::init()
#30 /var/www/nextcloud/console.php(49): require_once('/var/www/nextcl...')
#31 /var/www/nextcloud/occ(11): require_once('/var/www/nextcl...')
#32 {main}[ nc-update-nc-apps-auto ]
checking for updates...
An unhandled exception has been thrown:
Doctrine\DBAL\DBALException: Failed to connect to the database: An exception occurred in driver: SQLSTATE[HY000] [2002] No such file or directory in /var/www/nextcloud/lib/private/DB/Connection.php:72
Stack trace:
#0 /var/www/nextcloud/3rdparty/doctrine/dbal/lib/Doctrine/DBAL/Connection.php(1449): OC\DB\Connection->connect()
#1 /var/www/nextcloud/3rdparty/doctrine/dbal/lib/Doctrine/DBAL/Connection.php(892): Doctrine\DBAL\Connection->getWrappedConnection()
#2 /var/www/nextcloud/lib/private/DB/Connection.php(202): Doctrine\DBAL\Connection->executeQuery('SELECT * FROM `...', Array, Array, NULL)
#3 /var/www/nextcloud/3rdparty/doctrine/dbal/lib/Doctrine/DBAL/Query/QueryBuilder.php(206): OC\DB\Connection->executeQuery('SELECT * FROM `...', Array, Array)
#4 /var/www/nextcloud/lib/private/DB/QueryBuilder/QueryBuilder.php(248): Doctrine\DBAL\Query\QueryBuilder->execute()
#5 /var/www/nextcloud/lib/private/AppConfig.php(345): OC\DB\QueryBuilder\QueryBuilder->execute()
#6 /var/www/nextcloud/lib/private/AppConfig.php(110): OC\AppConfig->loadConfigValues()
#7 /var/www/nextcloud/lib/private/AppConfig.php(301): OC\AppConfig->getApps()
#8 /var/www/nextcloud/lib/private/legacy/OC_App.php(957): OC\AppConfig->getValues(false, 'installed_versi...')
#9 /var/www/nextcloud/lib/private/Server.php(668): OC_App::getAppVersions()
#10 /var/www/nextcloud/lib/private/AppFramework/Utility/SimpleContainer.php(155): OC\Server->OC\{closure}(Object(OC\Server))
#11 /var/www/nextcloud/3rdparty/pimple/pimple/src/Pimple/Container.php(118): OC\AppFramework\Utility\SimpleContainer->OC\AppFramework\Utility\{closure}(Object(Pimple\Container))
#12 /var/www/nextcloud/lib/private/AppFramework/Utility/SimpleContainer.php(122): Pimple\Container->offsetGet('OC\\Memcache\\Fac...')
#13 /var/www/nextcloud/lib/private/ServerContainer.php(156): OC\AppFramework\Utility\SimpleContainer->query('OC\\Memcache\\Fac...', true)
#14 /var/www/nextcloud/lib/private/Server.php(1677): OC\ServerContainer->query('OC\\Memcache\\Fac...')
#15 /var/www/nextcloud/lib/private/Server.php(1017): OC\Server->getMemCacheFactory()
#16 /var/www/nextcloud/lib/private/AppFramework/Utility/SimpleContainer.php(155): OC\Server->OC\{closure}(Object(OC\Server))
#17 /var/www/nextcloud/3rdparty/pimple/pimple/src/Pimple/Container.php(118): OC\AppFramework\Utility\SimpleContainer->OC\AppFramework\Utility\{closure}(Object(Pimple\Container))
#18 /var/www/nextcloud/lib/private/AppFramework/Utility/SimpleContainer.php(122): Pimple\Container->offsetGet('OCP\\Lock\\ILocki...')
#19 /var/www/nextcloud/lib/private/ServerContainer.php(156): OC\AppFramework\Utility\SimpleContainer->query('OCP\\Lock\\ILocki...', true)
#20 /var/www/nextcloud/lib/private/Server.php(1977): OC\ServerContainer->query('OCP\\Lock\\ILocki...')
#21 /var/www/nextcloud/lib/private/Files/View.php(118): OC\Server->getLockingProvider()
#22 /var/www/nextcloud/lib/private/Server.php(395): OC\Files\View->__construct()
#23 /var/www/nextcloud/lib/private/AppFramework/Utility/SimpleContainer.php(155): OC\Server->OC\{closure}(Object(OC\Server))
#24 /var/www/nextcloud/3rdparty/pimple/pimple/src/Pimple/Container.php(118): OC\AppFramework\Utility\SimpleContainer->OC\AppFramework\Utility\{closure}(Object(Pimple\Container))
#25 /var/www/nextcloud/lib/private/AppFramework/Utility/SimpleContainer.php(122): Pimple\Container->offsetGet('OC\\Files\\Node\\H...')
#26 /var/www/nextcloud/lib/private/ServerContainer.php(156): OC\AppFramework\Utility\SimpleContainer->query('OC\\Files\\Node\\H...', true)
#27 /var/www/nextcloud/lib/private/Server.php(1324): OC\ServerContainer->query('OC\\Files\\Node\\H...')
#28 /var/www/nextcloud/lib/base.php(595): OC\Server->boot()
#29 /var/www/nextcloud/lib/base.php(1091): OC::init()
#30 /var/www/nextcloud/console.php(49): require_once('/var/www/nextcl...')
#31 /var/www/nextcloud/occ(11): require_once('/var/www/nextcl...')
#32 {main}
[ nc-limits ] (ven 21 gen 2022, 08.27.55, CET)
Using 3018900480B for PHP
Using 6 PHP threads
Using 955968512 memory for the database

[ nc-limits ] (ven 21 gen 2022, 17.10.57, CET)
Using 3018900480B for PHP
Using 6 PHP threads
Using 955968512 memory for the database

[ nc-limits ] (gio 10 feb 2022, 18.00.30, CET)
Using 3018900480B for PHP
Using 6 PHP threads
Using 955968512 memory for the database

[ nc-export-ncp ] (gio 10 feb 2022, 18.02.44, CET)
configuration exported to /media/USBdrive//ncp-config_20220210.tar

[ nc-export-ncp ] (gio 10 feb 2022, 18.02.58, CET)
configuration exported to /media/USBdrive/ncp-config_20220210.tar

[ nc-backup ] (gio 10 feb 2022, 18.03.23, CET)
Error reading data directory. Is NextCloud running and configured?

[ nc-backup ] (gio 10 feb 2022, 18.03.45, CET)
Error reading data directory. Is NextCloud running and configured?

[ nc-update ] (gio 10 feb 2022, 18.04.06, CET)
Downloading updates
Performing updates
An unhandled exception has been thrown:
ArgumentCountError: Too few arguments to function OCA\PreviewGenerator\Command\Generate::__construct(), 0 passed in /var/www/nextcloud/lib/private/Console/Application.php on line 224 and at least 5 expected in /var/www/nextcloud/apps/previewgenerator/lib/Command/Generate.php:72
Stack trace:
#0 /var/www/nextcloud/lib/private/Console/Application.php(224): OCA\PreviewGenerator\Command\Generate->__construct()
#1 /var/www/nextcloud/lib/private/Console/Application.php(136): OC\Console\Application->loadCommandsFromInfoXml(Array)
#2 /var/www/nextcloud/console.php(99): OC\Console\Application->loadCommands(Object(Symfony\Component\Console\Input\ArgvInput), Object(Symfony\Component\Console\Output\ConsoleOutput))
#3 /var/www/nextcloud/occ(11): require_once('/var/www/nextcl...')
#4 {main}Error while applying update 1.45.0. Exiting...

[ nc-limits ] (gio 10 feb 2022, 18.05.40, CET)
Using 3018900480B for PHP
Using 6 PHP threads
Using 955968512 memory for the database

[ nc-backup ] (gio 10 feb 2022, 18.10.36, CET)
Error reading data directory. Is NextCloud running and configured?

[ nc-backup ] (gio 10 feb 2022, 18.12.17, CET)
Error reading data directory. Is NextCloud running and configured?

[ nc-update ] (gio 10 feb 2022, 18.15.46, CET)
Downloading updates
Performing updates
An unhandled exception has been thrown:
ArgumentCountError: Too few arguments to function OCA\PreviewGenerator\Command\Generate::__construct(), 0 passed in /var/www/nextcloud/lib/private/Console/Application.php on line 224 and at least 5 expected in /var/www/nextcloud/apps/previewgenerator/lib/Command/Generate.php:72
Stack trace:
#0 /var/www/nextcloud/lib/private/Console/Application.php(224): OCA\PreviewGenerator\Command\Generate->__construct()
#1 /var/www/nextcloud/lib/private/Console/Application.php(136): OC\Console\Application->loadCommandsFromInfoXml(Array)
#2 /var/www/nextcloud/console.php(99): OC\Console\Application->loadCommands(Object(Symfony\Component\Console\Input\ArgvInput), Object(Symfony\Component\Console\Output\ConsoleOutput))
#3 /var/www/nextcloud/occ(11): require_once('/var/www/nextcl...')
#4 {main}Error while applying update 1.45.0. Exiting...

[ nc-backup ] (gio 10 feb 2022, 18.20.52, CET)
Error reading data directory. Is NextCloud running and configured?

[ nc-webui ] (gio 10 feb 2022, 18.23.42, CET)
Enabling site ncp.
To activate the new configuration, you need to run:
systemctl reload apache2
ncp-web enabled

[ nc-webui ] (gio 10 feb 2022, 18.26.51, CET)
Site ncp disabled.
To activate the new configuration, you need to run:
systemctl reload apache2
ncp-web disabled

[ nc-backup ] (gio 10 feb 2022, 18.27.20, CET)
Error reading data directory. Is NextCloud running and configured?

[ nc-backup ] (gio 10 feb 2022, 18.42.11, CET)
Error reading data directory. Is NextCloud running and configured?

[ nc-webui ] (gio 10 feb 2022, 18.42.35, CET)
Enabling site ncp.
To activate the new configuration, you need to run:
systemctl reload apache2
ncp-web enabled

[ nc-passwd ] (gio 10 feb 2022, 18.44.18, CET)
password updated successfully


The output of your config.php file in /path/to/nextcloud (make sure you remove any identifiable information!):

$CONFIG = array (
  'passwordsalt' => '',
  'secret' => '',
  'trusted_domains' =>
  array (
    0 => 'localhost',
    1 => 'localip',
    4 => 'domain',
    11 => 'external_ip',
    3 => ''
    '' => '',
    14 => 'nextcloudpi',
  ),
  'datadirectory' => '/media/71cb21d2-e14c-470f-91d9-6950ef88e0fa/ncdata',
  'overwrite.cli.url' => '',
  'dbtype' => 'mysql',
  'version' => '20.0.11.1',
  'dbname' => 'nextcloud',
  'dbhost' => 'localhost',
  'dbport' => '',
  'dbtableprefix' => 'oc_',
  'mysql.utf8mb4' => true,
  'dbuser' => 'ncadmin',
  'dbpassword' => 'db_pass',
  'installed' => true,
  'mail_smtpmode' => 'sendmail',

The output of your Apache/nginx/system log in /var/log/____:

this shoulnd't be necessary

more info: I cannot update from ncp 1.44.5 to 1.45.0 because I get

Downloading updates
Performing updates
An unhandled exception has been thrown:
ArgumentCountError: Too few arguments to function OCA\PreviewGenerator\Command\Generate::__construct(), 0 passed in /var/www/nextcloud/lib/private/Console/Application.php on line 224 and at least 5 expected in /var/www/nextcloud/apps/previewgenerator/lib/Command/Generate.php:72
Stack trace:
#0 /var/www/nextcloud/lib/private/Console/Application.php(224): OCA\PreviewGenerator\Command\Generate->__construct()
#1 /var/www/nextcloud/lib/private/Console/Application.php(136): OC\Console\Application->loadCommandsFromInfoXml(Array)
#2 /var/www/nextcloud/console.php(99): OC\Console\Application->loadCommands(Object(Symfony\Component\Console\Input\ArgvInput), Object(Symfony\Component\Console\Output\ConsoleOutput))
#3 /var/www/nextcloud/occ(11): require_once('/var/www/nextcl...')
#4 {main}Error while applying update 1.45.0. Exiting...

I’m backing up to clean install a 64 bit version and change disks, so I didn’t bother about that, but the cause might be the same for everything

disabling the preview generator app did the job, allowing me to update nextcloudpi and backing up the files.