Introduction

This is the documentation for the instance types defined in instanceTypes.yaml.

Note The follow instance types are provided by OpenShift by default. They can be easily build and installed from source with:

$ kubectl kustomize > instanceTypes.yaml
$ kubectl apply -f instanceTypes.yaml

Overview

Structure

The available instance types are structured into two themes:

1. Workload agnostic - or general purpose
2. Workload specific

Instance Types of the first theme are a good starting point to run your workload. Once you know more about the requirements of your workload, you can start choosing a specific instance type of the second class.

The following diagram summarises the available instance types and their use-cases:

graph TD

classDef grp fill:white,stroke:lightgray,color:gray
classDef series fill:lightyellow,stroke:lightgray
classDef instancetype fill:

wrkld(Workload specific)
nwrkld(Workload agnostic)
class wrkld grp

wrkld:::grp --> Computeintensive:::series
Computeintensive([Compute intensive]):::series --> cx1:::instancetype

wrkld:::grp --> GPU:::series
GPU([GPU]):::series --> gn1:::instancetype

wrkld:::grp --> Memoryintensive:::series
Memoryintensive([Memory intensive]):::series --> m1:::instancetype

wrkld:::grp --> Networkintensive:::series
Networkintensive([Network intensive]):::series --> n1:::instancetype

nwrkld:::grp --> Generalpurpose:::series
Generalpurpose([General purpose]):::series --> u1:::instancetype

nwrkld:::grp --> Oversubscribed:::series
Oversubscribed([Oversubscribed]):::series --> uo1:::instancetype

Schema

Click in order to view the instanceType names schema

instanceTypeName = seriesName , "." , size;

seriesName = ( class | vendorClass ) , version;

class = "u" | "uo" | "cx" | "m" | "n";
vendorClass = "g" , vendorHint;
vendorHint = "n" | "i" | "a";
version = "1";

size = "small" | "medium" | "large" | [( "2" | "4" | "8" )] , "xlarge";

Series

.	CX	GN	M	N	U	UO
Has GPUs		✓
Hugepages			✓	✓
Overcommitted Memory						✓
Dedicated CPU	✓
Burstable CPU performance		✓	✓	✓	✓	✓
Isolated emulator threads	✓
vNUMA	✓
vCPU-To-Memory Ratio	1:4	1:4	1:8	1:4	1:2	1:2

CX Series

The CX Series provides exclusive compute resources for compute intensive applications.

CX is the abbreviation of "Compute Exclusive".

The exclusive resources are given to the compute threads of the VM. In order to ensure this, some additional cores (depending on the number of disks and NICs) will be requestedto offload the IO threading from cores dedicated to the workload. In addition, in this series, the NUMA topology of the used cores is provided to the VM.

CX Series Characteristics

Specific characteristics of this series are:

• Dedicated CPU - Physical cores are exclusively assigned to every vCPU in order to provide fixed and high compute guarantees to the workload
• Isolated emulator threads - Hypervisor emulator threads are isolated from the vCPUs in order to reduce emaulation related impact on the workload
• vCPU-To-Memory Ratio (1:4) - A vCPU-to-Memory ratio of 1:4, for less noise per node
• vNUMA - Physical NUMA topology is reflected in the guest in order to optimize guest sided cache utilization

CX Series Instance Types

The following instance types are available in this series:

Name	Cores	Memory
cx1.medium	1	4Gi
cx1.large	2	8Gi
cx1.2xlarge	8	32Gi
cx1.4xlarge	16	64Gi
cx1.8xlarge	32	128Gi

GN Series

The GN Series provides instances types intended for VMs with NVIDIA GPU resources attached.

GN is the abbreviation of "GPU NVIDIA".

This series is intended to be used with VMs consuming GPUs provided by the NVIDIA GPU Operator which is made available on OpenShift via OperatorHub.

GN Series Characteristics

Specific characteristics of this series are:

• Burstable CPU performance - The workload has a baseline compute performance but is permitted to burst beyond this baseline, if excess compute is available
• Has GPUs - Has GPUs predefined
• vCPU-To-Memory Ratio (1:4) - A vCPU-to-Memory ratio of 1:4, for less noise per node

GN Series Instance Types

The following instance types are available in this series:

Name	Cores	Memory
gn1.xlarge	4	16Gi
gn1.2xlarge	8	32Gi
gn1.4xlarge	16	64Gi
gn1.8xlarge	32	128Gi

M Series

The M Series provides resources for memory intensive applications.

M is the abbreviation of "Memory".

M Series Characteristics

Specific characteristics of this series are:

• Burstable CPU performance - The workload has a baseline compute performance but is permitted to burst beyond this baseline, if excess compute is available
• Hugepages - Hugepages are used in order to improve memory performance
• vCPU-To-Memory Ratio (1:8) - A vCPU-to-Memory ratio of 1:8, for much less noise per node

M Series Instance Types

The following instance types are available in this series:

Name	Cores	Memory
m1.large	2	16Gi
m1.xlarge	4	32Gi
m1.2xlarge	8	64Gi
m1.4xlarge	16	128Gi
m1.8xlarge	32	256Gi

N Series

The N Series provides resources for network intensive applications, like VNFs.

N is the abbreviation of "Network".

N Series Characteristics

Specific characteristics of this series are:

• Burstable CPU performance - The workload has a baseline compute performance but is permitted to burst beyond this baseline, if excess compute is available
• Hugepages - Hugepages are used in order to improve memory performance
• vCPU-To-Memory Ratio (1:4) - A vCPU-to-Memory ratio of 1:4, for less noise per node

N Series Instance Types

The following instance types are available in this series:

Name	Cores	Memory
n1.large	2	8Gi
n1.xlarge	4	16Gi
n1.2xlarge	8	32Gi

U Series

The U Series is quite neutral and provides resources for general purpose applications.

U is the abbreviation for "Universal", hinting at the fact that this family is providing general compute resources to workloads.

VMs of instance types will share physical CPU cores on a time-slice basis with other VMs.

U Series Characteristics

Specific characteristics of this series are:

• Burstable CPU performance - The workload has a baseline compute performance but is permitted to burst beyond this baseline, if excess compute is available
• vCPU-To-Memory Ratio (1:2) - A vCPU-to-Memory ratio of 1:2

U Series Instance Types

The following instance types are available in this series:

Name	Cores	Memory
u1.medium	1	2Gi
u1.large	2	4Gi
u1.2xlarge	4	8Gi
u1.4xlarge	8	16Gi
u1.8xlarge	16	32Gi

UO Series

The UO Series is based on the U Series, with the difference of being memory oversubscribed.

UO is the abbreviation for "Universal and Oversubscribed" hinting at the neutral attitude towards workloads and the fact that instances of this type are memory oversubscribed.

VMs of instance types will share physical CPU cores on a time-slice basis with other VMs.

UO Series Characteristics

Specific characteristics of this series are:

• Burstable CPU performance - The workload has a baseline compute performance but is permitted to burst beyond this baseline, if excess compute is available
• Overcommitted Memory - Memory is over-committed in order to achieve a higher workload density
• vCPU-To-Memory Ratio (1:2) - A vCPU-to-Memory ratio of 1:2

UO Series Instance Types

The following instance types are available in this series:

Name	Cores	Memory
uo1.large	2	4Gi
uo1.2xlarge	4	8Gi
uo1.4xlarge	8	16Gi
uo1.8xlarge	16	32Gi