In moodlecode/admin/tool/task/cli
Help screen shows:
[root@server cli]# php schedule_task.php
Scheduled cron tasks.
Options:
--execute=\\some\\task Execute scheduled task manually
--list List all scheduled tasks
--showsql Show sql queries before they are executed
--showdebugging Show developer level debugging information
-h, --help Print out this help
Example:
$sudo -u www-data /usr/bin/php admin/tool/task/cli/scheduled_task.php --execute=\\core\\task\\session_cleanup_task
List them first and pick out those that you think will help.
Then attempt executing them.
Because your cron has been off and is messed up think some of these task will take a long time and might appear to hang as well.
You could issue the command with a nohup which would give you the ability to kill the process ... you don't need another Zombie.
https://www.computerhope.com/unix/unohup.htm
You could use 'top' command after issuing the nohup php script to see how well things are going, me thinks.
'spirit of sharing', Ken