How to increase vm.max_map_count in a Plesk for Linux server?

Question

How to increase vm.max_map_count in a Plesk for Linux server?

Answer

Note: if direct SSH access to the server is not possible, contact the server administrator for further assistance.

Note: if container virtualization is used, these steps should be applied on a hardware node side.

1. Connect to the server via SSH;

2. increase the default value of vm.max_map_count parameter. An example of how to do that is shown below:

   # sysctl -w vm.max_map_count=655300
   vm.max_map_count = 655300

   Or:

   # echo 655350 > /proc/sys/vm/max_map_count

3. To change it permanently edit /etc/sysctl.conf with a text editor and add the following parameter with the new value. For example:

   vm.max_map_count=655350

4. Run the command to immediately apply the changes made in /etc/sysctl.conf:

   # sysctl -p

Additional information

The file /etc/sysctl.conf contains the maximum number of memory map areas a process may have. Memory map areas are used as a side-effect of calling malloc, directly by mmap and mprotect, and also when loading shared libraries.

While most applications need less than a thousand maps, certain programs, particularly malloc debuggers, may consume lots of them, e.g. up to one or two maps per allocation.

The default value is 65536.