Craft 3.7 permission denied error on install & migration - installation

Question

On a new Rackspace server, I am getting the following error whenever I try to install and/or migrate a Craft 3.7.0 site from local environment:
PHP Warning – yii\base\ErrorException session_start():open(/var/lib/php/session/sess_6d4r4eip8iotcfif9hlbi701ap, O_RDWR) failed: Permission denied (13)
1. in /my/path at line 152
{
if ($this->getIsActive()) {
return;
}
$this->registerSessionHandler();
$this->setCookieParamsInternal();
YII_DEBUG ? session_start() : #session_start();
if ($this->getUseStrictMode() && $this->_forceRegenerateId) {
$this->regenerateID();
$this->_forceRegenerateId = null;
}
if ($this->getIsActive()) {
Yii::info('Session started', __METHOD__);
$this->updateFlashCounters();
2. in /my/path/vendor/craftcms/cms/src/web/ErrorHandler.php at line 76– yii\base\ErrorHandler::handleError() 70717273747576777879808182 {
// Because: https://bugs.php.net/bug.php?id=74980
if (PHP_VERSION_ID >= 70100 && strpos($message, 'Narrowing occurred during type inference. Please file a bug report') !== false) {
return null;
}
return parent::handleError($code, $message, $file, $line);
}
/**
* #inheritdoc
*/
public function getExceptionName($exception)
3. craft\web\ErrorHandler::handleError()
4. in /my/path/vendor/yiisoft/yii2/web/Session.php at line 152– session_start() 146147148149150151152153154155156157158 }
$this->registerSessionHandler();
$this->setCookieParamsInternal();
YII_DEBUG ? session_start() : #session_start();
if ($this->getUseStrictMode() && $this->_forceRegenerateId) {
$this->regenerateID();
$this->_forceRegenerateId = null;
}
5. in /my/path/vendor/yiisoft/yii2/web/Session.php at line 751– yii\web\Session::open() 745746747748749750751752753754755756757 /**
* #param mixed $key session variable name
* #return bool whether there is the named session variable
*/
public function has($key)
{
$this->open();
return isset($_SESSION[$key]);
}
/**
* Updates the counters for flash messages and removes outdated flash messages.
* This method should only be called once in [[init()]]
etc.
I've tried checking the owner/group permissions, setting the chmod to 774 and 777, to no avail. Also cleared the storage/runtime folder and public/cpresources folder on each attempt.
What could be going on? Running PHP 7.4.2 and the Craft requirements are all met via checkit.php file.
Much appreciate the help in advance!

Answer 1

You can see that PHP is trying to write temp files to store the session in, which is failing because the PHP process doesn't have the correct permissions for that folder:
session_start():open(/var/lib/php/session/sess_6d4r4eip8iotcfif9hlbi701ap, O_RDWR) failed: Permission denied
You can solve this in a number of ways:
Change your PHP configuration to save session in a different folder that is writable by the process – see session_save_path. You would need to do this in your index.php and your craft file BEFORE craft is initiated.
Change the permissions of the folder in the error message above so the PHP process has write access to it.
Configure Craft to store sessions in the database instead. See How can I store Craft sessions in the database?