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