How to increase vm.max_map_count on a Plesk for Linux server June 24, 2024

Increasing the vm.max_map_count parameter on a Plesk for Linux server is required for applications (such as Elasticsearch) that need a higher number of memory map areas than the default limit.

Follow the steps:

1. Connect to the Server
   1. Access your server via SSH.
   2. If you do not have SSH access, contact your server administrator.
2. Increase vm.max_map_count Temporarily
   Run the following command as root or using sudo to increase the value until the next reboot:

   sysctl -w vm.max_map_count=655350

   Alternatively, you can use:

   sudo sh -c ‘echo 655350 > /proc/sys/vm/max_map_count’

3. Make the Change Permanent
   To ensure the setting persists after a reboot:
   1. Open the sysctl configuration file:

      vi /etc/sysctl.conf

   2. Add the following line at the end of the file:

      vm.max_map_count=655350

   3. Save and exit the file.
4. Apply the Changes
   Apply the configuration immediately without rebooting:

   sysctl -p

5. Verify the Change
   Confirm that the new value has been applied successfully:

   sysctl vm.max_map_count

   Expected output:

   vm.max_map_count = 655350

Notes:

• The /etc/sysctl.conf file controls kernel parameters, including the maximum number of memory map areas a process can use.
• The default value is 65536, which may be insufficient for certain applications.
• If your server uses container-based virtualisation, these changes must be applied on the hardware node.

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