While working on the server which has Cloudlinux CageFS Enabled you may cace issues with websites hosted on it which start showing you the 500 Internal server error. The errors may look like as mentioned below.
SoftException in Application.cpp:487: CageFS jail error Unable to mount /var/cagefs/55/cpaneluser/.cagefs -> /usr/share/cagefs-skeleton/var/.cagefs: Cannot allocate memory
[root@server1]# cagefsctl -M
mount: mount /proc on /usr/share/cagefs-skeleton/proc failed: Cannot allocate memory
Error: failed to mount /proc
You do not need to panic , this normally happens with the insufficient resources like RAM or Disk needed to run the cloudlinux working. You can either get the resource usage reduce or get higher resources for your server/VPS. Most of the times if its related to the ram overusage it can be solved by rebooting the server. to make sure that the RAM usage is hitting the server you can check it via linux commands like “Free -m” .
[root@server1~]# free -m
total used free shared buff/cache available
Mem: 64768 5883 53413 906 5470 58620
Swap: 0 0 0
Once confirm about the problem you can reboot the server and get it fix.