I recently upgraded from Magento 126.96.36.199 to 188.8.131.52. There is now a serious issue with the cronjob. The cron seems to load indefinitely until the whole website gets unreachable ..
Here is the error I get in the system.log:
2017-11-08T16:40:19+00:00 ERR (3): Warning: shell_exec(): Unable to execute '/bin/sh '/html/development/my-site/cron.sh' 'cron.php' -malways 1 \> /dev/null 2\>\&1 \&' in /html/development/my-site/cron.php on line 68
I temporarily disabled the cron with this line in the cron.php file:
$isShellDisabled = true;
The cronjob did work in the previous version. I don't unterstand what is causing this .. any idea ?
Can you check if PHP safe_mode is Off & shell_exec() is not included in disable_functions in php.ini?
Then, you could check if cron.php has permissions to be executable and the cron command is properly written.