I’ve seen several features of cPanel appear to malfunction, and upon reviewing /usr/local/cpanel/logs/error_log, I’d see something similar to this:
Out of memory during request for 2180 bytes, total sbrk() is 130234368 bytes!
Common places this has been known to occur:
- In Webmail (Horde and Roundcube) when opening large attachments
- Using cPanel’s perl module installer
You could legitimately be out of RAM, but most likely the cause is cPanel’s internal memory limit. You can raise this in WHM > Tweak Settings:
“The maximum memory a cPanel process can use before it is killed off (in megabytes). Values less than 128 megabytes can not be specified. A value of “0” will disable the memory limits.”
Or you can adjust the maxmem setting in /var/cpanel/cpanel.config.