Firecracker.MachineConfig (firecracker v0.1.0)

View Source

Configures the virtual machine's hardware specifications in Firecracker.

This module defines core hardware characteristics of the VM including CPU count, memory size, and various performance-related features.

Fields

  • :mem_size_mib - Required. Memory size in mebibytes (MiB)
  • :vcpu_count - Required. Number of virtual CPUs to allocate
  • :smt - Optional. Whether to enable Simultaneous Multithreading
  • :track_dirty_pages - Optional. Enable dirty page tracking for memory operations
  • :huge_pages - Optional. Use huge pages for memory allocation ("None", "2M")

Post-boot Behavior

All configuration fields can be modified after boot.

Notes

  • Memory size is specified in mebibytes (MiB), not megabytes
  • vCPU count should match your workload requirements
  • Disabling SMT can improve security at the cost of performance
  • Dirty page tracking is useful for live migration scenarios
  • Huge pages can improve memory performance for large VMs

Summary

Types

t()

Types

t()

@type t() :: %Firecracker.MachineConfig{
  applied?: boolean(),
  cpu_template: String.t() | nil,
  huge_pages: String.t() | nil,
  mem_size_mib: pos_integer(),
  smt: boolean() | nil,
  track_dirty_pages: boolean() | nil,
  vcpu_count: pos_integer()
}