503 error on user websites caused by CageFS
Check the logs
tail /var/log/apache2/stderr.logFri Apr 29 12:32:02 2022 (95855): Fatal Error Unable to create lock file: Bad file descriptor (9)
To fix the issue follow this guide: Apache: Fatal Error Unable to create lock file: Bad file descriptor (9)
Disable CsageFS for that user:
/usr/sbin/cagefsctl --disable $username
and enable it back:
/usr/sbin/cagefsctl --enable $username
![Screen Shot 2020 06 23 at 09.57.51 - WARNING: [pool user_USERNAME] server reached pm.max_children setting (25), consider raising it](https://i0.wp.com/administrator.pejcic.rs/wp-content/uploads/2026/09/Screen-Shot-2020-06-23-at-09.57.51.png?resize=344%2C194&ssl=1 "WARNING: [pool user_USERNAME] server reached pm.max_children setting (25), consider raising it")
![2023 08 28 12 15 - node[175421]: pthread_create: Resource temporarily unavailable](https://i0.wp.com/administrator.pejcic.rs/wp-content/uploads/2023/08/2023-08-28_12-15.png?resize=344%2C194&ssl=1 "node[175421]: pthread_create: Resource temporarily unavailable")