Unable to find writable var_dir

#0 /var/www/html/erototoys.com/app/code/core/Mage/Core/Model/Config/Options.php(122): Mage_Core_Model_Config_Options->getVarDir()
#1 /var/www/html/erototoys.com/app/code/core/Mage/Core/Model/Config/Options.php(39): Mage_Core_Model_Config_Options->getCacheDir()
#2 /var/www/html/erototoys.com/app/Mage.php(202): Mage_Core_Model_Config_Options->getDir('cache')
#3 /var/www/html/erototoys.com/app/code/core/Mage/Core/Model/App.php(885): Mage::getBaseDir('cache')
#4 /var/www/html/erototoys.com/app/code/core/Mage/Core/Model/App.php(911): Mage_Core_Model_App->getCache()
#5 /var/www/html/erototoys.com/app/code/core/Mage/Core/Model/Config.php(342): Mage_Core_Model_App->loadCache('config_global')
#6 /var/www/html/erototoys.com/lib/Varien/Simplexml/Config.php(382): Mage_Core_Model_Config->_loadCache('config_global')
#7 /var/www/html/erototoys.com/app/code/core/Mage/Core/Model/Config.php(149): Varien_Simplexml_Config->loadCache()
#8 /var/www/html/erototoys.com/app/code/core/Mage/Core/Model/App.php(236): Mage_Core_Model_Config->init(Array)
#9 /var/www/html/erototoys.com/app/Mage.php(424): Mage_Core_Model_App->init('', 'store', Array)
#10 /var/www/html/erototoys.com/app/Mage.php(443): Mage::app('', 'store', Array)
#11 /var/www/html/erototoys.com/index.php(54): Mage::run()
#12 {main}