sysctl vm.max_map_count

• What it does: Displays the maximum number of memory map areas a process may have.

• Why it matters: Important for applications like Elasticsearch, Docker, or large Java apps that use many memory-mapped files.

• Default: Often 65530, but high-memory apps may need it increased (e.g., to 262144).

  sysctl vm.max_map_count   --> check max mapping count
  

• sysctl -w vm.max_map_count=262144   -->run the command where is running on the same server