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Chapter 5. Kernel parameters

ParameterDescription

BridgeNfCallArpTables

Configures sysctl net.bridge.bridge-nf-call-arptables key. The default value is 1.

BridgeNfCallIp6Tables

Configures sysctl net.bridge.bridge-nf-call-ip6tables key. The default value is 1.

BridgeNfCallIpTables

Configures sysctl net.bridge.bridge-nf-call-iptables key. The default value is 1.

ExtraKernelModules

Hash of extra kernel modules to load.

ExtraKernelPackages

List of extra kernel related packages to install.

ExtraSysctlSettings

Hash of extra sysctl settings to apply.

FsAioMaxNumber

The kernel allocates aio memory on demand, and this number limits the number of parallel aio requests; the only drawback of a larger limit is that a malicious guest could issue parallel requests to cause the kernel to set aside memory. Set this number at least as large as 128 * (number of virtual disks on the host) Libvirt uses a default of 1M requests to allow 8k disks, with at most 64M of kernel memory if all disks hit an aio request at the same time. The default value is 0.

InotifyIntancesMax

Configures sysctl fs.inotify.max_user_instances key. The default value is 1024.

IsolCpusList

List of logical CPU ids whic need to be isolated from the host processes. This input is provided to the tuned profile cpu-partitioning to configure systemd and repin interrupts (IRQ repinning).

KernelArgs

Kernel Args to apply to the host.

KernelArgsDeferReboot

When enabled, nodes will not get rebooted automatically by tripleo-kernel if KernelArgs have been changed. Operators will have to manually reboot nodes after the deployment or update process is completed. Leaving this enabled during a scale-up operation will prevent reboot on new nodes. This might cause deployment errors as the KernelArgs will not be applied. The default value is False.

KernelDisableIPv6

Configures sysctl net.ipv6.{default/all}.disable_ipv6 keys. The default value is 0.

KernelIpForward

Configures net.ipv4.ip_forward key. The default value is 1.

KernelIpNonLocalBind

Configures net.ipv{4,6}.ip_nonlocal_bind key. The default value is 1.

KernelPidMax

Configures sysctl kernel.pid_max key. The default value is 1048576.

NeighbourGcThreshold1

Configures sysctl net.ipv4.neigh.default.gc_thresh1 value. This is the minimum number of entries to keep in the ARP cache. The garbage collector will not run if there are fewer than this number of entries in the cache. The default value is 1024.

NeighbourGcThreshold2

Configures sysctl net.ipv4.neigh.default.gc_thresh2 value. This is the soft maximum number of entries to keep in the ARP cache. The garbage collector will allow the number of entries to exceed this for 5 seconds before collection will be performed. The default value is 2048.

NeighbourGcThreshold3

Configures sysctl net.ipv4.neigh.default.gc_thresh3 value. This is the hard maximum number of entries to keep in the ARP cache. The garbage collector will always run if there are more than this number of entries in the cache. The default value is 4096.

NodeRebootWaitTimeout

Timeout in seconds to specify the wait time for ansible node reboot. The default value is 900.

RoleNetIpMap

NO DESCRIPTION

TunedProfileName

Tuned Profile to apply to the host. The default value is throughput-performance.