Warning: session_start(): open(/tmp/magento/var/session/sess_qo1n6vtsa9b3kvoh2q78ase7e4, O_RDWR) failed: No space left on device (28)  in /var/www/html/magento/app/code/core/Mage/Core/Model/Session/Abstract/Varien.php on line 134

#0 [internal function]: mageCoreErrorHandler(2, 'session_start()...', '/var/www/html/m...', 134, Array)
#1 /var/www/html/magento/app/code/core/Mage/Core/Model/Session/Abstract/Varien.php(134): session_start()
#2 /var/www/html/magento/app/code/core/Mage/Core/Model/Session/Abstract/Varien.php(223): Mage_Core_Model_Session_Abstract_Varien->start('frontend')
#3 /var/www/html/magento/app/code/core/Mage/Core/Model/Session/Abstract.php(84): Mage_Core_Model_Session_Abstract_Varien->init('core', 'frontend')
#4 /var/www/html/magento/app/code/core/Mage/Core/Model/Session.php(42): Mage_Core_Model_Session_Abstract->init('core', 'frontend')
#5 /var/www/html/magento/app/code/core/Mage/Core/Model/Config.php(1357): Mage_Core_Model_Session->__construct(Array)
#6 /var/www/html/magento/app/Mage.php(471): Mage_Core_Model_Config->getModelInstance('core/session', Array)
#7 /var/www/html/magento/app/Mage.php(485): Mage::getModel('core/session', Array)
#8 /var/www/html/magento/app/code/core/Mage/Core/Controller/Varien/Action.php(493): Mage::getSingleton('core/session', Array)
#9 /var/www/html/magento/app/code/core/Mage/Core/Controller/Front/Action.php(69): Mage_Core_Controller_Varien_Action->preDispatch()
#10 /var/www/html/magento/app/code/core/Mage/Checkout/controllers/CartController.php(129): Mage_Core_Controller_Front_Action->preDispatch()
#11 /var/www/html/magento/app/code/core/Mage/Core/Controller/Varien/Action.php(407): Mage_Checkout_CartController->preDispatch()
#12 /var/www/html/magento/app/code/core/Mage/Core/Controller/Varien/Router/Standard.php(254): Mage_Core_Controller_Varien_Action->dispatch('index')
#13 /var/www/html/magento/app/code/core/Mage/Core/Controller/Varien/Front.php(172): Mage_Core_Controller_Varien_Router_Standard->match(Object(Mage_Core_Controller_Request_Http))
#14 /var/www/html/magento/app/code/core/Mage/Core/Model/App.php(365): Mage_Core_Controller_Varien_Front->dispatch()
#15 /var/www/html/magento/app/Mage.php(692): Mage_Core_Model_App->run(Array)
#16 /var/www/html/magento/index.php(90): Mage::run('', 'store')
#17 {main}