我正在为网络负载平衡（NLB）IIS 10群集提供基于CakePHP 3.x的站点。 php文件驻留在外部DFS共享上。在启用调试的情况下运行时，CakePHP会引发以下错误：
2017-08-16 13:45:39 Error: Fixture creation for "requests" failed "SQLSTATE[HY000]: General error: 10 disk I/O error"
2017-08-16 13:45:39 Warning: Warning (512): Fixture creation for "requests" failed "SQLSTATE[HY000]: General error: 10 disk I/O error" in [\\MY.DOMAIN.COM\WEBAPPS\Sites\some_site\vendor\cakephp\cakephp\src\TestSuite\Fixture\TestFixture.php, line 306]
Request URL: /
Client IP: 10.1.2.250
Trace:
Cake\Error\BaseErrorHandler::handleError() - CORE\src\Error\BaseErrorHandler.php, line 146
Cake\TestSuite\Fixture\TestFixture::create() - CORE\src\TestSuite\Fixture\TestFixture.php, line 306
DebugKit\Model\Table\RequestsTable::ensureTables() - ROOT\vendor\cakephp\debug_kit\src\Model\Table\LazyTableTrait.php, line 56
DebugKit\Model\Table\RequestsTable::initialize() - ROOT\vendor\cakephp\debug_kit\src\Model\Table\RequestsTable.php, line 52
Cake\ORM\Table::__construct() - CORE\src\ORM\Table.php, line 290
Cake\ORM\Locator\TableLocator::_create() - CORE\src\ORM\Locator\TableLocator.php, line 212
Cake\ORM\Locator\TableLocator::get() - CORE\src\ORM\Locator\TableLocator.php, line 179
Cake\ORM\TableRegistry::get() - CORE\src\ORM\TableRegistry.php, line 110
DebugKit\ToolbarService::saveData() - ROOT\vendor\cakephp\debug_kit\src\ToolbarService.php, line 172
DebugKit\Routing\Filter\DebugBarFilter::afterDispatch() - ROOT\vendor\cakephp\debug_kit\src\Routing\Filter\DebugBarFilter.php, line 139
Cake\Event\EventManager::_callListener() - CORE\src\Event\EventManager.php, line 426
Cake\Event\EventManager::dispatch() - CORE\src\Event\EventManager.php, line 391
Cake\Http\ActionDispatcher::dispatchEvent() - CORE\src\Event\EventDispatcherTrait.php, line 78
Cake\Http\ActionDispatcher::dispatch() - CORE\src\Http\ActionDispatcher.php, line 100
Cake\Http\BaseApplication::__invoke() - CORE\src\Http\BaseApplication.php, line 83
Cake\Http\Runner::__invoke() - CORE\src\Http\Runner.php, line 65
Cake\Routing\Middleware\RoutingMiddleware::__invoke() - CORE\src\Routing\Middleware\RoutingMiddleware.php, line 62
Cake\Http\Runner::__invoke() - CORE\src\Http\Runner.php, line 65
Cake\Routing\Middleware\AssetMiddleware::__invoke() - CORE\src\Routing\Middleware\AssetMiddleware.php, line 88
Cake\Http\Runner::__invoke() - CORE\src\Http\Runner.php, line 65
AssetCompress\Middleware\AssetCompressMiddleware::__invoke() - ROOT\vendor\markstory\asset_compress\src\Middleware\AssetCompressMiddleware.php, line 56
Cake\Http\Runner::__invoke() - CORE\src\Http\Runner.php, line 65
Cake\Error\Middleware\ErrorHandlerMiddleware::__invoke() - CORE\src\Error\Middleware\ErrorHandlerMiddleware.php, line 81
Cake\Http\Runner::__invoke() - CORE\src\Http\Runner.php, line 65
Cake\Http\Runner::run() - CORE\src\Http\Runner.php, line 51
Cake\Http\Server::run() - CORE\src\Http\Server.php, line 90
require - ROOT\webroot\index.php, line 37
[main] - ROOT\index.php, line 16
IIS对项目根文件夹（在网络共享上）具有完全写入权限。 CakePHP错误日志已捕获上述信息。证明了这一点。所以这绝对不是文件/文件夹权限。
导致此错误的原因是什么以及如何修复？
谢谢。