6 VPP requires *'hugepages'* to run. VPP will overwrite existing hugepage settings
7 when VPP is installed. By default, VPP sets the number of hugepages on a system
8 to 1024 2M hugepages (1G hugepages are no longer supported). This is the number
9 of hugepages on the system, not just used by VPP.
11 When VPP is installed, the following file is copied to the system and used to apply the
12 hugepage settings on VPP installation and system reboot:
14 .. code-block:: console
16 $ cat /etc/sysctl.d/80-vpp.conf
17 # Number of 2MB hugepages desired
20 # Must be greater than or equal to (2 * vm.nr_hugepages).
23 # All groups allowed to access hugepages
24 vm.hugetlb_shm_group=0
26 # Shared Memory Max must be greator or equal to the total size of hugepages.
27 # For 2MB pages, TotalHugepageSize = vm.nr_hugepages * 2 * 1024 * 1024
28 # If the existing kernel.shmmax setting (cat /sys/proc/kernel/shmmax)
29 # is greater than the calculated TotalHugepageSize then set this parameter
30 # to current shmmax value.
31 kernel.shmmax=2147483648
33 Depending on how the system is being used, this file can be updated to adjust
34 the number of hugepages reserved on a system. Below are some examples of
37 For a small VM with minimal workload:
39 .. code-block:: console
43 kernel.shmmax=1073741824
45 For a large system running multiple VMs, each needing its own set of hugepages:
47 .. code-block:: console
50 vm.max_map_count=66560
51 kernel.shmmax=68719476736
56 If VPP is being run in a Virtual Machine (VM), the VM must have hugepage
57 backing. When VPP is installed, it will attempt to overwrite existing
58 hugepage setting. If the VM does not have hugepage backing, this will fail,
59 but this may go unnoticed. When the VM is rebooted, on system startup,
60 *'vm.nr_hugepages'* will be reapplied, will fail, and the VM will abort kernel
61 boot, locking up the VM. To avoid this scenario, ensure the VM has enough