Nova Compute

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• aa-profile-mode | string

  Default: disable

  Control experimental apparmor profile for Nova daemons (nova-compute, nova-api and nova-network). This is separate to the apparmor profiles for KVM VMs which is controlled by libvirt and is on, in enforcing mode, by default. Valid settings: 'complain', 'enforce' or 'disable'. . Apparmor is disabled by default for the Nova daemons.

• action-managed-upgrade | boolean

  If True enables OpenStack upgrades for this charm via Juju actions. You will still need to set openstack-origin to the new repository but instead of an upgrade running automatically across all units, it will wait for you to execute the openstack-upgrade action for this charm on each unit. If False it will revert to existing behavior of upgrading all units on config change.

• authorized-keys-path | string

  Default: {homedir}/.ssh/authorized_keys

  Only used when migration-auth-type is set to ssh. . Full path to authorized_keys file, can be useful for systems with non-default AuthorizedKeysFile location. It will be formatted using the following variables: . homedir - user's home directory username - username .

• block-device-allocate-retries | int

  Default: 300

  Number of times to check for a volume to be available before attaching it during server create. The timeout is calculated with block-device-allocate-retries-interval(default: 3s) so the default timeout with the charm is 15 minutes (300 retries at 3-seconds interval).

• block-device-allocate-retries-interval | int

  Seconds between block device allocation retries. The default value is 3. Please refer to the description of the "block-device-allocate-retries" config for more details.

• bluestore-compression-algorithm | string

  Compressor to use (if any) for pools requested by this charm. . NOTE: The ceph-osd charm sets a global default for this value (defaults to 'lz4' unless configured by the end user) which will be used unless specified for individual pools.

• bluestore-compression-max-blob-size | int

  Chunks larger than this are broken into smaller blobs sizing BlueStore compression max blob size before being compressed on pools requested by this charm.

• bluestore-compression-max-blob-size-hdd | int

  Value of BlueStore compression max blob size for rotational media on pools requested by this charm.

• bluestore-compression-max-blob-size-ssd | int

  Value of BlueStore compression max blob size for solid state media on pools requested by this charm.

• bluestore-compression-min-blob-size | int

  Chunks smaller than this are never compressed on pools requested by this charm.

• bluestore-compression-min-blob-size-hdd | int

  Value of BlueStore compression min blob size for rotational media on pools requested by this charm.

• bluestore-compression-min-blob-size-ssd | int

  Value of BlueStore compression min blob size for solid state media on pools requested by this charm.

• bluestore-compression-mode | string

  Policy for using compression on pools requested by this charm. . 'none' means never use compression. 'passive' means use compression when clients hint that data is compressible. 'aggressive' means use compression unless clients hint that data is not compressible. 'force' means use compression under all circumstances even if the clients hint that the data is not compressible.

• bluestore-compression-required-ratio | float

  The ratio of the size of the data chunk after compression relative to the original size must be at least this small in order to store the compressed version on pools requested by this charm.

• bridge-interface | string

  Default: br100

  Bridge interface to be configured.

• bridge-ip | string

  Default: 11.0.0.1

  IP to be assigned to bridge interface.

• bridge-netmask | string

  Default: 255.255.255.0

  Netmask to be assigned to bridge interface.

• ceph-osd-replication-count | int

  Default: 3

  This value dictates the number of replicas Ceph must make of any object it stores within the Nova RBD pool. Of course, this only applies if using Ceph as a backend store. Note that once the Nova RBD pool has been created, changing this value will not have any effect (although it can be changed in Ceph by manually configuring your Ceph cluster).

• ceph-pool-weight | int

  Default: 30

  Defines a relative weighting of the pool as a percentage of the total amount of data in the Ceph cluster. This effectively weights the number of placement groups for the pool created to be appropriately portioned to the amount of data expected. For example, if the ephemeral volumes for the OpenStack compute instances are expected to take up 20% of the overall configuration then this value would be specified as 20. Note - it is important to choose an appropriate value for the pool weight as this directly affects the number of placement groups which will be created for the pool. The number of placement groups for a pool can only be increased, never decreased - so it is important to identify the percent of data that will likely reside in the pool.

• config-flags | string

  Comma-separated list of key=value config flags. These values will be placed in the nova.conf [DEFAULT] section.

• cpu-allocation-ratio | float

  The per physical core -> virtual core ratio to use in the Nova scheduler. . Increasing this value will increase instance density on compute nodes at the expense of instance performance.

• cpu-dedicated-set | string

  Sets compute/cpu_dedicated_set option in nova.conf and defines which physical CPUs will be used for dedicated guest vCPU resources. . This option is only available from the Train release and later. If non-empty it will silently stop the 'vcpu-pin-set' option from being used.

• cpu-mode | string

  Set to 'host-model' to clone the host CPU feature flags; to 'host-passthrough' to use the host CPU model exactly; to 'custom' to use a named CPU model; to 'none' to not set any CPU model. If virt_type='kvm|qemu', it will default to 'host-model', otherwise it will default to 'none'. Defaults to 'host-passthrough' for ppc64el, ppc64le if no value is set.

• cpu-model | string

  Set to a named libvirt CPU model (see names listed in /usr/share/libvirt/cpu_map.xml). Only has effect if cpu_mode='custom' and virt_type='kvm|qemu'. . Starting from the Train release this option is deprecated and has been superseded by the 'cpu-models' option. This option will be silently ignored if the 'cpu-models' option is non-empty.

• cpu-model-extra-flags | string

  Space delimited list of specific CPU flags for libvirt.

• cpu-models | string

  An ordered, comma separated, list of the CPU models supported by the host. The models on the list must be ordered according to the features they support. The less advanced models must precede more advanced, feature rich, models. . Example: 'SandyBridge,IvyBridge,Haswell,Broadwell' . CPU models are listed in:

  • /usr/share/libvirt/cpu_map.xml (libvirt version < 4.7.0)
  • /usr/share/libvirt/cpu_map/*.xml (libvirt version >= 4.7.0) . This option only has effect if cpu_mode='custom' and virt_type='kvm|qemu'.

• cpu-shared-set | string

  Sets compute/cpu_shared_set option in nova.conf and defines which physical CPUs will be used for best-effort guest vCPU resources. Currently only used by libvirt driver to place guest emulator threads when hw:emulator_threads_policy:share is set. . This option is only available from the Rocky release and later.

• customize-failure-domain | boolean

  Juju propagates availability zone information to charms from the underlying machine provider such as MAAS and this option allows the charm to use JUJU_AVAILABILITY_ZONE to set default_availability_zone for Nova nodes. This option overrides the default-availability-zone charm config setting only when the Juju provider sets JUJU_AVAILABILITY_ZONE.

• database | string

  Default: nova

  Nova database name.

• database-user | string

  Default: nova

  Username for database access.

• debug | boolean

  Enable debug logging.

• default-availability-zone | string

  Default: nova

  Default compute node availability zone. . This option determines the availability zone to be used when it is not specified in the VM creation request. If this option is not set, the default availability zone 'nova' is used. If customize-failure-domain is set to True, it will override this option only if an AZ is set by the Juju provider. If JUJU_AVAILABILITY_ZONE is not set, the value specified by this option will be used regardless of customize-failure-domain's setting. . NOTE: Availability zones must be created manually using the 'openstack aggregate create' command. .

• default-ephemeral-format | string

  Default: ext4

  The default format used to create an ephemeral volume. This format is used only if the volume ostype is default otherwise Nova ostype defaults are used (ext4 for linux, ntfs for windows) and these can be overriden using the virt-mkfs-cmds option. Possible values: ext2 ext3 ext4 xfs ntfs (only for Windows guests)

• disk-allocation-ratio | float

  Increase the amount of disk space that nova can overcommit to guests. . Increasing this value will increase instance density on compute nodes with an increased risk of hypervisor storage becoming full.

• disk-cachemodes | string

  Specific cachemodes to use for different disk types e.g: file=directsync,block=none

• ec-profile-crush-locality | string

  (lrc plugin) The type of the CRUSH bucket in which each set of chunks defined by l will be stored. For instance, if it is set to rack, each group of l chunks will be placed in a different rack. It is used to create a CRUSH rule step such as step choose rack. If it is not set, no such grouping is done.

• ec-profile-device-class | string

  Device class from CRUSH map to use for placement groups for erasure profile - valid values: ssd, hdd or nvme (or leave unset to not use a device class).

• ec-profile-durability-estimator | int

  (shec plugin - c) The number of parity chunks each of which includes each data chunk in its calculation range. The number is used as a durability estimator. For instance, if c=2, 2 OSDs can be down without losing data.

• ec-profile-helper-chunks | int

  (clay plugin - d) Number of OSDs requested to send data during recovery of a single chunk. d needs to be chosen such that k+1 <= d <= k+m-1. Larger the d, the better the savings.

• ec-profile-k | int

  Default: 1

  Number of data chunks that will be used for EC data pool. K+M factors should never be greater than the number of available zones (or hosts) for balancing.

• ec-profile-locality | int

  (lrc plugin - l) Group the coding and data chunks into sets of size l. For instance, for k=4 and m=2, when l=3 two groups of three are created. Each set can be recovered without reading chunks from another set. Note that using the lrc plugin does incur more raw storage usage than isa or jerasure in order to reduce the cost of recovery operations.

• ec-profile-m | int

  Default: 2

  Number of coding chunks that will be used for EC data pool. K+M factors should never be greater than the number of available zones (or hosts) for balancing.

• ec-profile-name | string

  Name for the EC profile to be created for the EC pools. If not defined a profile name will be generated based on the name of the pool used by the application.

• ec-profile-plugin | string

  Default: jerasure

  EC plugin to use for this applications pool. The following list of plugins are acceptable - jerasure, lrc, isa, shec, clay.

• ec-profile-scalar-mds | string

  (clay plugin) specifies the plugin that is used as a building block in the layered construction. It can be one of jerasure, isa, shec (defaults to jerasure).

• ec-profile-technique | string

  EC profile technique used for this applications pool - will be validated based on the plugin configured via ec-profile-plugin. Supported techniques are ‘reed_sol_van’, ‘reed_sol_r6_op’, ‘cauchy_orig’, ‘cauchy_good’, ‘liber8tion’ for jerasure, ‘reed_sol_van’, ‘cauchy’ for isa and ‘single’, ‘multiple’ for shec.

• ec-rbd-metadata-pool | string

  Name of the metadata pool to be created (for RBD use-cases). If not defined a metadata pool name will be generated based on the name of the data pool used by the application. The metadata pool is always replicated, not erasure coded.

• enable-live-migration | boolean

  Configure libvirt or lxd for live migration. . Live migration support for lxd is still considered experimental. . NOTE: This also enables passwordless SSH access for user 'root' between compute hosts.

• enable-resize | boolean

  Enable instance resizing. . NOTE: This also enables passwordless SSH access for user 'nova' between compute hosts.

• enable-vtpm | boolean

  Enable emulated Trusted Platform Module support on the hypervisors. A key manager, e.g. Barbican, is a required service for this capability to be enabled.

• encrypt | boolean

  Encrypt block devices used for Nova instances using dm-crypt, making use of vault for encryption key management; requires a relation to vault.

• ephemeral-device | string

  Block devices to use for storage of ephemeral disks to support nova instances; generally used in-conjunction with 'encrypt' to support data-at-rest encryption of instance direct attached storage volumes.

• ephemeral-unmount | string

  Cloud instances provide ephemeral storage which is normally mounted on /mnt. . Setting this option to the path of the ephemeral mountpoint will force an unmount of the corresponding device so that it can be used for as the backing store for local instances. This is useful for testing purposes (cloud deployment is not a typical use case).

• extra-repositories | string

  Additional apt repositories to configure as installation sources for apt. The acceptable format of this option are those values accepted by the add-apt-repository command. Multiple repositories can be provided by separating the entries with a comma. Examples include:

  ppa:user/repository deb http://myserver/path/to/repo stable main ppa:userA/repository1, ppa:userB/repository2

• flat-interface | string

  Default: eth1

  Network interface on which to build bridge.

• force-raw-images | boolean

  Default: True

  Force conversion of backing images to raw format. Note that the conversion process in Pike uses O_DIRECT calls - certain file systems do not support this, for example ZFS; e.g. if using the LXD provider with ZFS backend, this option should be set to False.

• harden | string

  Apply system hardening. Supports a space-delimited list of modules to run. Supported modules currently include os, ssh, apache and mysql.

• hugepages | string

  The percentage of system memory to use for hugepages e.g. '10%' or the total number of 2M hugepages - e.g. '1024'. For a systemd system (wily and later) the preferred approach is to enable hugepages via kernel parameters set in MAAS and systemd will mount them automatically. . NOTE: For hugepages to work it must be enabled on the machine deployed to. This can be accomplished by setting kernel parameters on capable machines in MAAS, tagging them and using these tags as constraints in the model.

• initial-cpu-allocation-ratio | float

  The initial value of per physical core -> virtual core ratio to use in the Nova scheduler; this may be overridden at runtime by the placement API. . Increasing this value will increase instance density on compute nodes at the expense of instance performance. . This option doesn't have any effect on clouds running a release < Stein.

• initial-disk-allocation-ratio | float

  The initial value of this disk allocation ratio. Increase the amount of disk space that nova can overcommit to guests. This may be overridden at runtime by the placement API. . Increasing this value will increase instance density on compute nodes with an increased risk of hypervisor storage becoming full. . This option doesn't have any effect on clouds running a release < Stein.

• initial-ram-allocation-ratio | float

  The initial value of physical RAM -> virtual RAM ratio to use in the Nova scheduler; this may be overridden at runtime by the placement API. . Increasing this value will increase instance density on compute nodes at the potential expense of instance performance. . NOTE: When in a hyper-converged architecture, make sure to make enough room for infrastructure services running on your compute hosts by adjusting this value. . This option doesn't have any effect on clouds running a release < Stein.

• inject-password | boolean

  Enable or disable admin password injection at boot time on hypervisors that use the libvirt back end (such as KVM, QEMU, and LXC). The random password appears in the output of the 'openstack server create' command.

• instances-path | string

  Path used for storing Nova instances data - empty means default of /var/lib/nova/instances.

• ksm | string

  Default: AUTO

  Set to 1 to enable KSM, 0 to disable KSM, and AUTO to use default settings. . Please note that the AUTO value works for qemu 2.2+ (> Kilo), older releases will be set to 1 as default.

• libvirt-image-backend | string

  Tell Nova which libvirt image backend to use. Supported backends are raw, qcow2, rbd and flat. If no backend is specified, the Nova default (qcow2) is used. NOTE: 'rbd' imagebackend is only supported with >= Juno. NOTE: 'flat' imagebackend is only supported with >= Newton and replaces 'raw'.

• libvirt-migration-network | string

  Specify a network in CIDR notation (192.168.0.0/24), which directs libvirt to use a specific network address as the live_migration_inbound_addr to make use of a dedicated migration network if possible. . Please note that if the migration binding has been declared and set, the primary address for that space has precedence over this configuration option. . This option doesn't have any effect on clouds running a release < Ocata.

• live-migration-completion-timeout | int

  Default: 800

  Time to wait, in seconds, for migration to successfully complete transferring data before aborting the operation. Value is per GiB of guest RAM + disk to be transferred, with lower bound of a minimum of 2 GiB. Should usually be larger than downtime-delay*downtime-steps Set to 0 to disable timeouts.

• live-migration-downtime | int

  Default: 500

  Maximum permitted downtime, in milliseconds, for live migration switchover. Will be rounded up to a minimum of 100ms. Use a large value if guest liveness is unimportant.

• live-migration-downtime-delay | int

  Default: 75

  Time to wait, in seconds, between each step increase of the migration downtime. Minimum delay is 10 seconds. Value is per GiB of guest RAM + disk to be transferred, with lower bound of a minimum of 2 GiB per device.

• live-migration-downtime-steps | int

  Default: 10

  Number of incremental steps to reach max downtime value. Will be rounded up to a minimum of 3 steps.

• live-migration-permit-auto-converge | boolean

  If live-migration is enabled, this option allows Nova to throttle down CPU when an on-going live migration is slow. This is superseded by 'live-migration-permit-post-copy'.

• live-migration-permit-post-copy | boolean

  If live-migration is enabled, this option allows Nova to switch an on-going live migration to post-copy mode. The switch will happen if the migration reaches 'live-migration-completion-timeout'. This supersedes 'live-migration-permit-auto-converge'.

• migration-auth-type | string

  Default: ssh

  TCP authentication scheme for libvirt live migration. Available options include ssh.

• multi-host | string

  Default: yes

  Whether to run nova-api and nova-network on the compute nodes. Note that nova-network is not available on Ussuri and later.

• nagios_context | string

  Default: juju

  Used by the nrpe-external-master subordinate charm. A string that will be prepended to instance name to set the host name in nagios. So for instance the hostname would be something like: . juju-myservice-0 . If you're running multiple environments with the same services in them this allows you to differentiate between them.

• nagios_servicegroups | string

  A comma-separated list of nagios servicegroups. If left empty, the nagios_context will be used as the servicegroup.

• neutron-physnets | string

  The physnets that are present on the host and NUMA affinity settings of that physnet for specific numa_nodes. . Example: 'foo:0;bar:0,1' '<physnet>:<numa-id>;<physnet>:<numa-id>,<numa-id>' . This option doesn't have any effect on clouds running a release < Rocky.

• neutron-tunnel | string

  A comma-separated list of NUMA node ids for tunnelled networking NUMA affinity. . Example: '0,1' . This option doesn't have any effect on clouds running a release < Rocky.

• notification-format | string

  Default: unversioned

  There are two types of notifications in Nova: legacy notifications which have an unversioned payload and newer notifications which have a versioned payload. . Setting this option to versioned will use the versioned notification concept, unversioned, the unversioned notification concept and finally both will use the two concepts. . Starting in the Pike release, the notification_format includes both the versioned and unversioned message notifications. Ceilometer does not yet consume the versioned message notifications, so intentionally make the default notification format unversioned until this is implemented. . Possible Values are both, versioned, unversioned.

• nova-config | string

  Default: /etc/nova/nova.conf

  Full path to Nova configuration file.

• num-pcie-ports | int

  Sets libvirt/num_pcie_ports option in nova.conf to assign more PCIe ports available for a VM. The default value relies on libvirt calculating amount of ports. The maximum value can be set is "28". . This option is only available from the Rocky release and later.

• openstack-origin | string

  Default: yoga

  Repository from which to install. May be one of the following: distro (default), ppa:somecustom/ppa, a deb URL sources entry or a supported Ubuntu Cloud Archive (UCA) release pocket. . Supported UCA sources include: . cloud:<series>-<openstack-release> cloud:<series>-<openstack-release>/updates cloud:<series>-<openstack-release>/staging cloud:<series>-<openstack-release>/proposed . For series=Precise we support UCA for openstack-release=

  • icehouse . For series=Trusty we support UCA for openstack-release=
  • juno
  • kilo
  • ... . NOTE: updating this setting to a source that is known to provide a later version of OpenStack will trigger a software upgrade. .

• os-internal-network | string

  The IP address and netmask of the OpenStack Internal network (e.g. 192.168.0.0/24) . This network will be used to bind vncproxy client.

• pci-alias | string

  The pci-passthrough-whitelist option of nova-compute charm is used for specifying which PCI devices are allowed passthrough. pci-alias is more a convenience that can be used in conjunction with Nova flavor properties to automatically assign required PCI devices to new instances. You could, for example, have a GPU flavor or a SR-IOV flavor: . pci-alias='{"vendor_id":"8086","product_id":"10ca","name":"a1"}' . This configures a new PCI alias 'a1' which will request a PCI device with a vendor id of 0x8086 and a product id of 10ca. To input a list of aliases, use the following syntax in this charm config option: . pci-alias='[{...},{...}]' . For more information about the syntax of pci_alias, refer to https://docs.openstack.org/ocata/config-reference/compute/config-options.html

• pci-passthrough-whitelist | string

  Sets the pci_passthrough_whitelist option in nova.conf which allows PCI passthrough of specific devices to VMs. . Example applications: GPU processing, SR-IOV networking, etc. . NOTE: For PCI passthrough to work IOMMU must be enabled on the machine deployed to. This can be accomplished by setting kernel parameters on capable machines in MAAS, tagging them and using these tags as constraints in the model.

• pool-type | string

  Default: replicated

  Ceph pool type to use for storage - valid values include ‘replicated’ and ‘erasure-coded’.

• prefer-ipv6 | boolean

  If True enables IPv6 support. The charm will expect network interfaces to be configured with an IPv6 address. If set to False (default) IPv4 is expected. . NOTE: these charms do not currently support IPv6 privacy extension. In order for this charm to function correctly, the privacy extension must be disabled and a non-temporary address must be configured/available on your network interface.

• rabbit-user | string

  Default: nova

  Username used to access RabbitMQ queue.

• rabbit-vhost | string

  Default: openstack

  RabbitMQ vhost.

• ram-allocation-ratio | float

  The physical RAM -> virtual RAM ratio to use in the Nova scheduler. . Increasing this value will increase instance density on compute nodes at the potential expense of instance performance. . NOTE: When in a hyper-converged architecture, make sure to make enough room for infrastructure services running on your compute hosts by adjusting this value.

• rbd-client-cache | string

  Enable/disable RBD client cache. Leaving this value unset will result in default Ceph RBD client settings being used (RBD cache is enabled by default for Ceph >= Giant). Supported values here are 'enabled' or 'disabled'.

• rbd-pool | string

  Default: nova

  RBD pool to use with Nova libvirt RBDImageBackend. Only required when you have libvirt-image-backend set to 'rbd'.

• reserved-host-disk | int

  Amount of disk resource in MB to reserve for the host. Defaults to 0MB.

• reserved-host-memory | int

  Default: 512

  Amount of memory in MB to reserve for the host. Defaults to 512MB.

• reserved-huge-pages | string

  Sets a reserved amount of huge pages per NUMA nodes which are used by third-party components. Semicolons are used as separator. . reserved_huge_pages = node:0,size:2048,count:64;node:1,size:1GB,count:1 . The above will consider 64 pages of 2MiB on NUMA node 0 and 1 page of 1GiB on NUMA node 1 reserved. They will not be used by Nova to map guests memory.

• restrict-ceph-pools | boolean

  Optionally restrict Ceph key permissions to access pools as required.

• resume-guests-state-on-host-boot | boolean

  This option determines whether to start guests that were running before the host rebooted.

• send-notifications-to-logs | boolean

  Ensure notifications are included in the log files. It will set an additional log driver for Oslo messaging notifications.

• sysctl | string

  Default: { net.ipv4.neigh.default.gc_thresh1 : 128, net.ipv4.neigh.default.gc_thresh2 : 28672, net.ipv4.neigh.default.gc_thresh3 : 32768, net.ipv6.neigh.default.gc_thresh1 : 128, net.ipv6.neigh.default.gc_thresh2 : 28672, net.ipv6.neigh.default.gc_thresh3 : 32768, net.nf_conntrack_max : 1000000, net.netfilter.nf_conntrack_buckets : 204800, net.netfilter.nf_conntrack_max : 1000000 }

  YAML formatted associative array of sysctl values, e.g.: '{ kernel.pid_max : 4194303 }'

• use-internal-endpoints | boolean

  OpenStack mostly defaults to using public endpoints for internal communication between services. If set to True this option will configure services to use internal endpoints where possible.

• use-multipath | boolean

  Use a multipath connection for iSCSI or FC volumes. Enabling this feature causes libvirt to login, discover and scan available targets before presenting the disk via device mapper (/dev/mapper/XX) to the VM instead of a single path (/dev/disk/by-path/XX). If changed after deployment, each VM will require a full stop/start for changes to take affect.

• use-syslog | boolean

  Setting this to True will allow supporting services to log to syslog.

• vcpu-pin-set | string

  Sets vcpu_pin_set option in nova.conf which defines which PCPUs that instance vCPUs can or cannot use. For example '^0,^2' to reserve two cpus for the host. . Starting from the Train release this option is deprecated and has been superseded by the 'cpu-shared-set' and 'cpu-dedicated-set' options. This option will be silently ignored if the 'cpu-dedicated-set' option is non-empty.

• verbose | boolean

  Enable verbose logging.

• virt-mkfs-cmds | string

  Nova-compute will default to using mkfs.vfat as the default method of formatting disks e.g. ephemeral volumes. If alternate commands are required they can be provided here as a comma-separated list with the format <os_type>=<mkfs command> e.g. 'default=mkfs.ext4,windows=mkfs.ntfs'.

• virt-type | string

  Default: kvm

  Virtualisation flavor. The only supported flavor is kvm.

  Other native libvirt flavors available for testing only: uml, lxc, qemu.

  NOTE: Changing the virtualisation flavor post-deployment is not supported.

• virtio-net-rx-queue-size | int

  Sets libvirt/rx_queue_size option in nova.conf. Larger queues sizes for virtio-net devices increases networking performance by amortizing vCPU preemption and avoiding packet drops. Only works with Rocky and later, since QEMU 2.7.0 and libvirt 2.3.0. Default value 256. Authorized values [256, 512, 1024].

• virtio-net-tx-queue-size | int

  Sets libvirt/tx_queue_size option in nova.conf. Larger queues sizes for virtio-net devices increases networking performance by amortizing vCPU preemption and avoiding packet drops. Only works with Rocky and later, since QEMU 2.10.0 and libvirt 3.7.0. Default value 256. Authorized values [256, 512, 1024].

• worker-multiplier | float

  The CPU core multiplier to use when configuring worker processes for this services e.g. metadata-api. By default, the number of workers for each daemon is set to twice the number of CPU cores a service unit has. This default value will be capped to 4 workers unless this configuration option is set.