BSP System Dimensioning Guide, CEE R6
Cloud Execution Environment

Contents

1Introduction
1.1Target Group
1.2System Characteristics

2

CEE System
2.1System Configurations
2.1.1Reference Configurations
2.1.2Certified Configuration

3

HW Requirements
3.1Summary of Blade Configuration
3.2Network Configuration
3.2.1Network Requirements for Distributed Storage, ScaleIO
3.3Firewall Requirement
3.4CPU Configuration
3.4.1Compute Host
3.4.2ScaleIO Host
3.5RAM Configuration
3.5.1Introduction
3.5.2Compute Server without vCIC and vFuel
3.5.3Compute Server with vCIC
3.5.4Compute Server with vFuel
3.5.5Compute Server with vCIC and vFuel
3.5.6ScaleIO Server with MDM/TB and SDS
3.6Storage Configuration
3.6.1Local Storage Disk Space
3.6.2Disk Requirements for Atlas
3.6.3Disk Requirements for Nova Snapshots
3.6.4Disk Requirements for Distributed Storage (ScaleIO)

4

Characteristics
4.1General System Limits
4.2Orchestration Interface
4.3Tenant Execution Environment
4.3.1Performance
4.3.2Resiliency
4.4Network
4.4.1Performance
4.4.2Resiliency
4.4.3Tenant Network Limitations
4.5Storage
4.5.1Limitations
4.5.2VM Migration with NoMigration Policy Set
4.5.3Resiliency
4.6In-Service Performance

5

System Limitations
5.1OpenStack Deviations
5.2SW Configurations and Options
5.2.1Allocation of Memory
5.2.2Allocation of vCPU
5.2.3Collocation of vCIC, vFuel, and Atlas
5.2.4Number of Parallel Root Volume Operations
5.3Not Supported
5.3.1Dashboard Does Not Support Internet Explorer
5.4Limitations and Workarounds
5.5Update Limitations
5.6Hardware Platform Limitations

Reference List

1   Introduction

This document describes the characteristics of Cloud Execution Environment (CEE) to enable dimensioning and understanding the limitations of CEE. It also describes requirements on HW combinations required for running CEE. The application can have additional requirements.

Storage is measured in gibibyte (GiB), tebibyte (TiB), and mebibyte (MiB) in this document.
1 GiB is equivalent to 1.074 GB.

The following words are used in this document with the meaning specified below:

vNIC A virtual network interface card (vNIC) provides connectivity between the Cloud SDN Switch (CSS) and a VM. A configuration can provide several vNICs to a VM.
Interface A network interface. Can be either a physical NIC (PHY) providing CSS with board external connectivity, or a virtual NIC connecting CSS to a VM.
PMD thread CSS uses a Poll Mode Driver (PMD) technique that continuously polls incoming packets from the NICs, that is, interrupts are not used. To be able to reliably handle all incoming packets, a software continuously polls the NIC queues for packets to be handled. This software is executing in one or more threads that are called PMD threads. The execution environment for the PMD threads is isolated from the Linux scheduler to be able to reliably handle a high sustained packet flow without interrupts or delays caused by being scheduled out.
vCIC host A host running Compute and vCIC. There are three vCIC hosts in Multi-Server deployments of CEE.
Compute host A host running Compute without vCIC

1.1   Target Group

Cloud Infrastructure providers and application designers.

1.2   System Characteristics

The characteristic features of CEE are the following:

For information on system limitations, see Section 5.

For BSP characteristics refer to the BSP product documentation.

2   CEE System

This section describes CEE system configurations and capabilities.

2.1   System Configurations

CEE is a scalable system used with HW products from different vendors. CEE offers a set of configurations.

2.1.1   Reference Configurations

Reference configurations offer the possibility to build and scale a cloud system on specified HW, such as servers, switches, and storage.

BSP can include one to six subracks with a maximum of 12 blades in each subrack, therefore, the biggest available configuration can contain up to 72 blades altogether in six subracks.

2.1.2   Certified Configuration

Certified configurations are a subset of reference configurations. Certified CEE configurations have been documented and tested by the Ericsson Cloud organization.

The certified configuration for CEE R6 consists of the following HW components:

3   HW Requirements

This section describes generic hardware and firmware requirements for CEE, based on the certified Ericsson CEE R6 HW.

Complying with the outlined HW requirements does not in any way imply Ericsson CEE certification. HW deployment outside the already certified ones requires system integration work.

The server, switching, and optional storage components of the HW environment are shown in fg-CeeHwEnvironmentBsp_eps Figure 1:

Figure 0   CEE HW Environment with BSP HW

Figure 1   CEE HW Environment with BSP HW

For information on the supported BSP 8100 HW, see Table 41. For more information, refer to the BSP document: BSP Technical Product Description, Reference [1].

3.1   Summary of Blade Configuration

This section describes HW requirements for blades.

Table 1    HW Configuration Example, GEP5

Aspect

Requirement

CPU

1 x Intel Xeon E5-2658 v2 processor (10 cores per processor, 2 Hyperthreads per core), 20 Hyperthreads available

RAM

64 GiB

NIC

4*10GE Intel Niantic and 2*1GE unspecified (Management)

Onboard Disk

  • 1200 GiB SSD (GEP5-64-1200)

  • 400 GiB DISK (GEP5-64-400)

  • 8 GiB (GEP5-64)

Management
Interface

EBS/BSP Out of band management


Table 2    HW Configuration Example, GEP7

Aspect

Requirement

CPU

1 x Intel Xeon E5-2658 v4 processor (14 cores per processor, 2 Hyperthreads per core), 28 Hyperthreads available

RAM

128 GiB

NIC

4*10GE Fortville

Onboard Disk

  • 1600 GiB SSD (GEP7-128-X16)

  • 8 GiB (GEP7-128-X

Management
Interface

EBS/BSP Out of band management


Note:  
SR-IOV is not supported for BSP HW.

For the characteristics of the GEP blade refer to the BSP documentation.

3.2   Network Configuration

This section describes HW configuration for networking.

For network configuration refer to the BSP documentation.

3.2.1   Network Requirements for Distributed Storage, ScaleIO

The following requirements must be fulfilled:

Network:

Parameters and configuration in ScaleIO that will affect dimensioning:

3.3   Firewall Requirement

During test of the CEE Certified Configuration, a Juniper EX 4550 has been used as BGW and a Juniper SRX 3400 as Firewall.

All Juniper SRX High-End series Firewalls provide a similar set of features. SRX can be equipped with a flexible number of Services Processing Cards (SPC), I/O Cards (IOC), and Network Processing Cards (NPC), allowing the system configuration to support a balance of performance and port density. Suitable firewall HW setup depends on expected traffic volumes and sessions. More information can be found in supplier datasheets, on the Juniper Networks homepage, Reference [2].

3.4   CPU Configuration

Refer to the Configuration File Guide for more information about the configuration procedure.

The number of available CPU IDs depends on the CPU model.

3.4.1   Compute Host

Table 3 and fig-CPU-allocation-BSP-eps Figure 2 give an example for automatic CPU allocation for VMs, OVS, vCIC, and vFuel. This allocation is valid for GEP5 with Intel Xeon E5-2658 v2 processor.

If the number of cores in the used processor type differs from the number of cores in this example, the number of cores allocated to the VMs must be adjusted.

The example describes the CPU allocation at a server that runs vCIC and vFuel. If vCIC or vFuel are not used on the server, their CPUs are allocated for the tenant VMs.

Table 3    Automatic CPU Allocation on GEP5 with Intel Xeon E5-2658 v2 Processor, for VMs, OVS, vCIC, and vFuel in a Compute Host

CPU Owner

Allocated CPU ID

Tenant VM

8,18, 9,19

OVS(1)

1,11

OVS control process(2)

0 (2)

vCIC(3)

4,14, 5,15, 6,16 7,17

vFuel

3,13

Host OS(4)

0,10, 2,12

If ScaleIO is installed, then 1–5 CPU threads are used for SDC.

(1)  To achieve a more predictable performance, allocate only one CPU per core for OVS. See Section 3.4.1.1 for more information.

(2)  The process does not get a CPU for its exclusive use. A configuration parameter specifies one of the host OS CPUs to be used by the OVS control process.

(3)  The vCIC can be allocated on cores that are over allocated and shared with the application. In such cases, it must be ensured that the application sharing resources with the vCIC dont exhaust the vCIC resources.

(4)  In some use-cases only one core is allocated to the host OS as explained in Section 3.4.1.2.


Table 4    Automatic CPU Allocation on GEP7 with Intel Xeon E5-2658 v4 Processor, for VMs, OVS, vCIC, and vFuel in a Compute Host

CPU Owner

Allocated CPU ID

Tenant VM

8,22, 9,23, 10,24, 11,25, 12,26, 13,27

OVS(1)

1,15

OVS control process(2)

0 tnote-OVS-control-process-BSP

vCIC(3)

4,18, 5,19, 6,20 7,21

vFuel

3,17

Host OS(4)

0,14, 2,16

If ScaleIO is installed, then 1–5 CPU threads are used for SDC.

(1)  To achieve a more predictable performance, allocate only one CPU per core for OVS. See Section 3.4.1.1 for more information.

(2)  The process does not get a CPU for its exclusive use. A configuration parameter specifies one of the host OS CPUs to be used by the OVS control process.

(3)  The vCIC can be allocated on cores that are over allocated and shared with the application. In such cases, it must be ensured that the application sharing resources with the vCIC dont exhaust the vCIC resources.

(4)  In some use-cases only one core is allocated to the host OS as explained in Section 3.4.1.2.


Figure 1   Automatic CPU Allocation of the Respective Resource Owner on GEP5 with Intel Xeon E5-2658 v2 Processor for VMs, OVS, vCIC, and vFuel in a Compute Host

Figure 2   Automatic CPU Allocation of the Respective Resource Owner on GEP5 with Intel Xeon E5-2658 v2 Processor for VMs, OVS, vCIC, and vFuel in a Compute Host

Figure 2   Automatic CPU Allocation of the Respective Resource Owner on GEP7 with Intel Xeon E5-2658 v4 Processor for VMs, OVS, vCIC, and vFuel in a Compute Host

Figure 3   Automatic CPU Allocation of the Respective Resource Owner on GEP7 with Intel Xeon E5-2658 v4 Processor for VMs, OVS, vCIC, and vFuel in a Compute Host

3.4.1.1   Allocating Single CPUs for OVS

To achieve a more predictable OVS performance, only a single CPU must be allocated to OVS from each CPU core reserved for OVS PMD threads. The other CPU on the same core, also called hyper-thread sibling, must be isolated, that is, not used by the host OS process scheduler, and is free from any extra load that can negatively influence the OVS performance.

To achieve the described allocation, the following settings must be performed:

3.4.1.2   Allocating One Core to the Host OS

However the recommended CPU allocation to the host OS is two cores for each Compute host, for some use-cases, where a single or very few VMs are used on each Compute host, it can be possible to reduce the host OS allocation to one core.
Having a single core allocated for the host OS can impact the characteristics of the system. For example, actions such as starting, stopping, and migrating VMs can become slower, and it can also impact the performance of other VMs on the same host. Before using a system with a single core allocated to the Host OS in a production environment, sufficient testing must be performed. Beside other checks, this testing must include the capacity and performance test of the VM during the time of performing life cycle management operations for other VMs running on the same host. While performing such test, the processor load for the host OS must be monitored carefully for deviation from a steady state.

3.4.2   ScaleIO Host

Table 5 shows the minimum number of cores to be allocated to the CPU owners in a ScaleIO host.

Table 5    Minimum Number of Allocated Cores in a ScaleIO Host

CPU Owner

Minimum Number of Allocated Cores

Host OS

2

Meta Data Manager/Tie-Breaker (MDM/TB)

1

SDS

2–4

3.5   RAM Configuration

This section describes the optimal RAM configuration for the CEE.

Refer to the Configuration File Guide for more information about the configuration procedure.

Each Neutron network created consumes RAM in the vCIC, and it influences the maximum number of virtual tenant networks. See Section 4.4.3 for more information.

The RAM size on GEP5-64-400 and GEP5-64-1200 boards is 64 GiB. The RAM size on GEP7-128-X16 and GEP7-128-X boards is 128 GiB.

Running vCIC, vFuel, or both on the server modifies the optimal memory allocation. The subsections below describe the possible cases for 128 and 64 GiB memory.

See the following cases:

Section 3.5.1 provides general information about RAM configuration in CEE.

3.5.1   Introduction

The default configuration for the Host OS on Compute nodes is 8 GiB. More memory can be reserved for the Host OS by setting the relevant configuration parameters. The needed amount of memory depends on the values of a number of other parameters as described below.

The memory used for the VMs is allocated to huge pages. This is the memory visible from the inside of the VMs. The 1 GiB huge pages are referred to as Tenant VM in the RAM reservation tables of the upcoming sections. In addition to the 1 GiB huge pages, the VMs need memory allocated from the host OS. This memory is used, for example, to emulate devices used by the virtual machine. It is hard to predict the amount of host OS memory used by the emulator since, for example, it depends on the type and number of the used devices. A small VM consumes less than 100 MiB, while it can grow to several hundred MiB in specific cases. About 300 MiB host OS memory would be enough for each virtual machine but we must double it and calculate with 600 MiB as explained below.

In a system using the NUMA architecture, the NUMA location of VMs must be considered. The available memory, that is, the huge pages and the Host OS memory, are evenly distributed between the NUMA nodes. By design, OpenStack Nova allocates VMs on the first NUMA node that fits the VM. Apart from the VMs running on both NUMA nodes, the VMs allocate memory from the NUMA node on which they are running. In a worst case scenario where all VMs are allocated on the same NUMA node, all the memory for the VMs will be allocated from the same NUMA node. In such a scenario most of the memory on the other NUMA node will be unused, and half of the memory on the Compute node will be free. To be on the safe side in a dual socket system, the 300 MiB host OS memory per VM must be doubled to cover the case where all VMs are allocated on the same NUMA node.

The host OS memory usage for processes other than the VMs depends on the CPU reservations. The host OS uses the unreserved CPUs. By default, CEE allocates two cores to the host OS on NUMA node 0. This means that most of the memory used by the Host OS will be allocated from NUMA node 0. In some scenarios it is preferred to run the host OS on both NUMA nodes. It can be achieved by modifying the CPU reservation.

Note:  
In order to allocate as little memory for the host OS as possible, memory profiling of the host OS for the specific scenario is recommended.

3.5.2   Compute Server without vCIC and vFuel

Table 6 and Table 7 specify the volumes allocated to the resource owners. Host Operating System (OS) is not included, so the tables contain 120 and 56 GiB, respectively.

Table 8 and Table 9 contain the total memory sizes.

Table 6    Memory Allocation for System with 128 GiB RAM

RAM Resource Owner

Hugepage size (MiB)

Number of Hugepages


(Count)

Total Size (GiB)

Tenant VM(1)

1024

118

118

OVS

2

1024

2

vCIC

-

-

-

vFuel

-

-

-

(1)  If Atlas is used, it runs at one of the hosts, and it uses 4 GiB of the RAM configured for the tenant VMs.


Table 7    Memory Allocation for System with 64 GiB RAM

RAM Resource Owner

Hugepage size (MiB)

Number of Hugepages


(Count)

Total Size (GiB)

Tenant VM(1)

1024

54

54

OVS

2

1024

2

vCIC

-

-

-

vFuel

-

-

-

(1)  If Atlas is used, it runs at one of the hosts, and it uses 4 GiB of the RAM configured for the tenant VMs.


Table 8    Total Memory Sizes for System with 128 GiB RAM

RAM Resource Owner

Total Size (GiB)

Tenant VM(1)

118

OVS

2

vCIC

-

vFuel

-

Host OS(2)

8 (2)

Total (with host OS)

128

(1)  If Atlas is used, it runs at one of the hosts, and it uses 4 GiB of the RAM configured for the tenant VMs.

(2)  If ScaleIO is installed, SDC uses 0.05 GiB of the RAM configured for the host OS.


Table 9    Total Memory Sizes for System with 64 GiB RAM

RAM Resource Owner

Total Size (GiB)

Tenant VM(1)

54

OVS

2

vCIC

-

vFuel

-

Host OS(2)

8 (2)

Total (with host OS)

64

(1)  If Atlas is used, it runs at one of the hosts, and it uses 4 GiB of the RAM configured for the tenant VMs.

(2)  If ScaleIO is installed, SDC uses 0.05 GiB of the RAM configured for the host OS.


3.5.3   Compute Server with vCIC

Table 10 and Table 11 specify the volumes allocated to the resource owners. Host OS is not included, so the tables contain 114 and 50 GiB, respectively.

Table 12 and Table 13 contain the total memory sizes.

Table 10    Memory Allocation for System with 128 GiB RAM

RAM Resource Owner

Hugepage size (MiB)

Number of Hugepages


(Count)

Total Size (GiB)

Tenant VM(1)

1024

82

82

OVS

2

1024

2

vCIC

1024

30

30

vFuel

-

-

-

(1)  If Atlas is used, it runs at one of the hosts, and it uses 4 GiB of the RAM configured for the tenant VMs.


Table 11    Memory Allocation for System with 64 GiB RAM

RAM Resource Owner

Hugepage size (MiB)

Number of Hugepages


(Count)

Total Size (GiB)

Tenant VM(1)

1024

18

18

OVS

2

1024

2

vCIC

1024

30

30

vFuel

-

-

-

(1)  If Atlas is used, it runs at one of the hosts, and it uses 4 GiB of the RAM configured for the tenant VMs.


Table 12    Total Memory Sizes for System with 128 GiB RAM

RAM Resource Owner

Total Size (GiB)

Tenant VM(1)

82

OVS

2

vCIC

30

vFuel

-

Host OS(2)

14 (2)

Total (with host OS)

128

(1)  If Atlas is used, it runs at one of the hosts, and it uses 4 GiB of the RAM configured for the tenant VMs.

(2)  If ScaleIO is installed, SDC uses 0.05 GiB of the RAM configured for the host OS.


Table 13    Total Memory Sizes for System with 64 GiB RAM

RAM Resource Owner

Total Size (GiB)

Tenant VM(1)

18

OVS

2

vCIC

30

vFuel

-

Host OS(2)

14 (2)

Total (with host OS)

64

(1)  If Atlas is used, it runs at one of the hosts, and it uses 4 GiB of the RAM configured for the tenant VMs.

(2)  If ScaleIO is installed, SDC uses 0.05 GiB of the RAM configured for the host OS.


3.5.4   Compute Server with vFuel

Table 14 and Table 15 specify the volumes allocated to the resource owners. Host OS is not included, so the tables contain 120 and 56 GiB, respectively.

Table 16 and Table 17 contain the total memory sizes.

Table 14    Memory Allocation for System with 128 GiB RAM

RAM Resource Owner

Hugepage size (MiB)

Number of Hugepages


(Count)

Total Size (GiB)

Tenant VM(1)

1024

115

115

OVS

2

1024

2

vCIC

-

-

-

vFuel

1024

3

3

(1)  If Atlas is used, it runs at one of the hosts, and it uses 4 GiB of the RAM configured for the tenant VMs.


Table 15    Memory Allocation for System with 64 GiB RAM

RAM Resource Owner

Hugepage size (MiB)

Number of Hugepages


(Count)

Total Size (GiB)

Tenant VM(1)

1024

51

51

OVS

2

1024

2

vCIC

-

-

-

vFuel

1024

3

3

(1)  If Atlas is used, it runs at one of the hosts, and it uses 4 GiB of the RAM configured for the tenant VMs.


Table 16    Total Memory Sizes for System with 128 GiB RAM

RAM Resource Owner

Total Size (GiB)

Tenant VM(1)

115

OVS

2

vCIC

-

vFuel

3

Host OS(2)

8 (2)

Total (with host OS)

128

(1)  If Atlas is used, it runs at one of the hosts, and it uses 4 GiB of the RAM configured for the tenant VMs.

(2)  If ScaleIO is installed, SDC uses 0.05 GiB of the RAM configured for the host OS.


Table 17    Total Memory Sizes for System with 64 GiB RAM

RAM Resource Owner

Total Size (GiB)

Tenant VM(1)

51

OVS

2

vCIC

-

vFuel

3

Host OS(2)

8 (2)

Total (with host OS)

64

(1)  If Atlas is used, it runs at one of the hosts, and it uses 4 GiB of the RAM configured for the tenant VMs.

(2)  If ScaleIO is installed, SDC uses 0.05 GiB of the RAM configured for the host OS.


3.5.5   Compute Server with vCIC and vFuel

Table 18 and Table 19 specify the volumes allocated to the resource owners. Host OS is not included, so the tables contain 114 and 50 GiB, respectively

Table 20 and Table 21 contain the total memory sizes.

Table 18    Memory Allocation for System with 128 GiB RAM

RAM Resource Owner

Hugepage size (MiB)

Number of Hugepages


(Count)

Total Size (GiB)

Tenant VM(1)

1024

79

79

OVS

2

1024

2

vCIC

1024

30

30

vFuel

1024

3

3

(1)  If Atlas is used, it runs at one of the hosts, and it uses 4 GiB of the RAM configured for the tenant VMs.


Table 19    Memory Allocation for System with 64 GiB RAM

RAM Resource Owner

Hugepage size (MiB)

Number of Hugepages


(Count)

Total Size (GiB)

Tenant VM(1)

1024

15

15

OVS

2

1024

2

vCIC

1024

30

30

vFuel

1024

3

3

(1)  If Atlas is used, it runs at one of the hosts, and it uses 4 GiB of the RAM configured for the tenant VMs.


Table 20    Total Memory Sizes for System with 128 GiB RAM

RAM Resource Owner

Total Size (GiB)

Tenant VM(1)

79

OVS

2

vCIC

30

vFuel

3

Host OS(2)

14 (2)

Total (with host OS)

128

(1)  If Atlas is used, it runs at one of the hosts, and it uses 4 GiB of the RAM configured for the tenant VMs.

(2)  If ScaleIO is installed, SDC uses 0.05 GiB of the RAM configured for the host OS.


Table 21    Total Memory Sizes for System with 64 GiB RAM

RAM Resource Owner

Total Size (GiB)

Tenant VM(1)

15

OVS

2

vCIC

30

vFuel

3

Host OS(2)

14 (2)

Total (with host OS)

64

(1)  If Atlas is used, it runs at one of the hosts, and it uses 4 GiB of the RAM configured for the tenant VMs.

(2)  If ScaleIO is installed, SDC uses 0.05 GiB of the RAM configured for the host OS.


3.5.6   ScaleIO Server with MDM/TB and SDS

Table 22 specifies the volumes allocated to the resource owners.

Table 23 contains the total memory sizes.

Table 22    Memory Allocation for System with 128 or 64 GiB RAM

RAM Resource Owner

Hugepage size (MiB)

Number of Hugepages


(Count)

Total Size (GiB)

MDM/TB

   

0.5

SDS

   

0.5

Table 23    Total Memory Sizes for System with 128 or 64 GiB RAM

RAM Resource Owner

Total Size (GiB)

MDM/TB

0.5

SDS

0.5

Host OS

8

Total (with host OS)

9

3.6   Storage Configuration

This section describes storage implementations and disk requirements.

On BSP, the supported storage solutions are local storage and distributed storage.

3.6.1   Local Storage Disk Space

This section lists requirements on disk space.

The following are supported as Compute hosts:

GEP5-64 has a 8 GiB disk, and GEP7-128 has a 16 GiB disk. CEE infrastructure use 7 GiB of those, and only 1 GiB is available for ephemeral storage for applications in the case of GEP5-64, and 9 GiB in the case of GEP7-128.. This small size is in practice only feasible for applications that run a RAM based file system and use anther compute host with disk for permanent storage as, for instance, done by IMS.

The disk space on GEP5-64 and GEP7-128 is not enough to store debug logs. Instead, the logs from Compute nodes are forwarded to the vCIC and stored in the vCIC. A different configuration can be used in BSP systems where all Compute hosts have a 400 GiB, 1200 GiB, or 1600 GiB disk, but such configurations are outside the scope of this document.

Only ROJ 208 867/5 GEP5-64-1200 and ROJ 208 844/7 GEP7-128-X16 are supported as hosts for vCIC.

Table 24    Compute Host with 8 GiB Disk, GEP5-64

Use

Compute Host

Root partition (host OS)

7 GiB

Logs and crash dumps

0 GiB

Remaining storage is for ephemeral storage for VMs

1 GiB

Table 25    Compute Host with 16 GiB Disk, GEP7-128

Use

Compute Host

Root partition (host OS)

7 GiB

Logs and crash dumps

0 GiB

Remaining storage is for ephemeral storage for VMs

9GiB

Table 26    vCIC Host and Compute Host, GEP boards

Use

vCIC Host


GEP5-64-1200


GEP7-128-X16

Compute Host


GEP5-64-400 (372 GiB) or
GEP5-64-1200 (1116 GiB)


GEP7-128-X

Note

Root partition (host OS)

50 GiB

50 GiB

 

Logs and crash dumps

40 GiB

40 GiB

 

vCIC Total

554 GiB

-

vCIC backup is not included.


See Table 27.

vCIC backup

52 GiB

-

 

Host total without vFuel and Atlas

696 GiB

90 GiB

 

vFuel

50 GiB

50

vFuel can be run on any Compute host and it uses disk from the ephemeral storage.


Limitation: Only two of the following can be run on the same Compute host:


Atlas

130 GiB

130

Atlas can be run on any Compute host and it uses disk from the ephemeral storage. The disk for Atlas is allocated by the CEE.


Limitation: Only two of the following can be run on the same Compute host:


Remaining storage is used as ephemeral storage for VMs.

Dimensioned depending on application need.

Dimensioned depending on application need.

Valid for boot from image.


Calculated from total disk reduced by used space.

Table 27    vCIC Disk Allocation

Note: This configuration is optimized for a BSP system equipped with 72 blades. Other configurations are possible, but outside the scope of this document.

Use

vCIC

Root partition (host OS)

50 GiB

Logs and crash dumps

224 GiB

Database for OpenStack and Zabbix (MySQL)

90 GiB

Database for Ceilometer (MongoDB)

70 GiB

Glance repository in Swift

100 GiB

vCIC sum

554 GiB

3.6.2   Disk Requirements for Atlas

When Virtual Machine (VM) images are loaded to Atlas as part of an .ova file, the image is temporarily stored in ephemeral storage in Atlas. To support loading of large images, the recommendation is to use 120 GiB for the Atlas ephemeral storage.

The Atlas VM occupies 120 GiB of the local disk on the compute node where it is running.

To reduce the disk allocated to Atlas, the size of the ephemeral disk can be reduced from 120 GiB to a minimum of 10 GiB. Since 30% of the ephemeral disk in Altas is used as temporary storage for .ova files, the size of the ephemeral disk needs to be adjusted according to the size of .ova files to be loaded. Using a reduced disk size of 10 GiB implies that it can be impossible to load .ova files that contain images larger than 3 GiB.

3.6.3   Disk Requirements for Nova Snapshots

Nova snapshots are stored in the /var/lib/glance partition of CIC nodes.

There are certain disk requirements for the Nova snapshots to work. Depending on the requirements and frequency on Nova snapshots, the system must be dimensioned with free disk space, according to the following guidelines:

3.6.4   Disk Requirements for Distributed Storage (ScaleIO)

Distributed Storage is optional. It can be used as the back end for Cinder.

The following requirements must be fulfilled:

4   Characteristics

This section describes the system characteristics of CEE.

4.1   General System Limits

For the list of system limits, see Table 28.

Table 28    General System Limits

Slogan

Limit

RAM used by the infrastructure(1)


See Section 3.5 for more information.

Compute Host:


  • Host OS: 8 GiB

  • OVS: 2 GiB

  • vFuel (if present): 3 GiB

vCIC Host:


Number of hosts (blades)

In the certified configuration 3 GEP5-64-1200 is used by the CEE infrastructure. Additional blades are needed for the VNF.


CEE supports 3–72 blades.

Number of cores occupied by infrastructure

In the certified configuration, the GEPs used as vCIC, vFuel and Atlas hosts are fully allocated to the CEE infrastructure.


On a Compute host with only tenant VMs:
1–2 cores are used by the host OS. The actual allocation depends on the application, and needs to be measured and dimensioned with the VNF in use.
1–4 cores are used for OVS. The actual allocation depend on the bandwidth needs from the VNF. See Section 4.4.1 for dimensioning rules.


All other cores are available for the VNF.


(1)  If Atlas is used, it runs at one of the hosts, and it uses 4 GiB of the RAM configured for the tenant VMs.


4.2   Orchestration Interface

The system limits for orchestration are listed in Table 29.

Table 29    Orchestration Limits

Slogan

Limits

Number of tenants

The maximum number of supported tenants is 50.


4.3   Tenant Execution Environment

This section describes the tenant-related limits on the environment.

4.3.1   Performance

Performance limits are listed in Table 30.

Table 30    Tenant Execution Performance

Slogan

Limits

Oversubscription

CPU, memory, and disk overcommit are not supported.


4.3.2   Resiliency

Resiliency-related tenant limits are listed in Table 31.

Table 31    Tenant Execution Resiliency

Slogan

Limits

Execution environment resiliency

The execution environment resiliency is relying on VM evacuation. States not conserved in storage are lost.


Each hypervisor instance is not redundant, and, apart from attached storage, assumed to be a knock-out unit.


4.4   Network

This section lists the limits on the network.

Neutron with VLAN segmentation is used.

4.4.1   Performance

The virtual switch (vSwitch) performance is measured by the packet rate (packets per second). The packet size has a very limited impact on the packet rate.

Note:  
Therefore, the forwarded amount of data (bit per second) increases if the packet size is increased.

Table 32 shows the throughput for PHY to VM traffic cases, and Table 33 for VM to VM cases. Table 34 provides dimensioning guidelines for specifying the amount of capacity that is safe to use. Table 35 describes vSwitch capacity for bandwidth-based scheduling.

Table 32    Measured Per Host Forwarding Capacity, 64 Byte Frames, PHY to VM

Slogan

Limits

Bidirectional traffic
from PHY

One PMD core is allocated to CSS. One HT is used by CSS, the other is idle.
Value = 3.70 Mpps

One PMD core is allocated to CSS. CSS uses both HTs.
Value = 4.64 Mpps

Two PMD cores are allocated to CSS. One HT in each core is used by CSS, the other is idle.
Value = 7.46 Mpps

Two PMD cores are allocated to CSS. CSS uses both HTs in each core. Value = 5.02 Mpps

Four cores allocated to CSS. One HT in each core is used by CSS, the other is idle.
Value = 7.27 Mpps


Table 33    Measured Guest VM Delivery Forwarding Capacity, 64 Byte Frames, VM to VM Intrahost Traffic

Slogan

Limits

Bidirectional traffic
from VM to VM

One PMD core is allocated to CSS. One HT is used by CSS, the other is idle.
Value = 3.10 Mpps

One PMD core is allocated to CSS. CSS uses both HTs.
Value = 4.63 Mpps

Two PMD cores are allocated to CSS. One HT in each core is used by CSS, the other is idle.
Value = 5.30 Mpps

Two PMD cores are allocated to CSS. CSS uses both HTs in each core. One vNIC per VM. Value = 4.39 Mpps

Four cores allocated to CSS. One HT in each core is used by CSS, the other is idle. One vNIC per VM. Value = 5.79 Mpps


Table 34    Dimensioning Capacity (Bidirectional Traffic)

Slogan

Limits

Total vSwitch capacity
(bidirectional traffic)

The total vSwitch capacity to be used for dimensioning is 80% of the per host forwarding value above.


It is different from the value of the "Measured per Host Forwarding Capacity", in order to take into account external effects impacting the deterministic behavior of the v Switch. The user can use a different value tuned for a specific system configuration, preferably based on measurements.

Per interface
vSwitch capacity
(bidirectional traffic)

The maximum dimensioning limit per interface is 80% of the per host forwarding value for one PMD core allocated to OVS, when the HT functionality is not used. If HT is used on the cores hosting OVS PMD threads, the value is 50% of the per host forwarding value.


If the number of interfaces is not bigger than the number of PMD threads, the 2 core values can be used as base, but this is not a likely scenario.


If more interfaces are configured than OVS-assigned PMD threads, the maximum dimensioning limit per interface is reduced by an additional factor: the number of interfaces divided by the number of OVS PMD threads, rounding any fraction to the next higher integer. Two examples: 7 interfaces and 3 OVS PMD threads => 7/3 = 2.33, round up => dividend is 3, which means that the capacity figure should be divided by 3; 9 interfaces and 3 OVS PMD threads => 9/3 = 3, there is no fraction so no round up => dividend is 3, which means that the capacity figure should be divided by 3.


It is not recommended to change the per interface limit, even if measurements indicate a higher capacity, as the behavior is highly dependent on the automatic distribution of the interfaces over the PMD threads.


Table 35    Virtual Switch Capacity for Bandwidth-Based Scheduling

Slogan

Limits

vSwitch capacity for bandwidth-based scheduling

The value is used as maximum threshold for the vSwitch bidirectional throughput per host. It is used to configure bandwidth-based scheduling per host when installing CEE. It must be below or, at most, equal to "Total vSwitch capacity (bidirectional traffic)" detailed in Table 34.

4.4.2   Resiliency

Network resiliency is listed in Table 36.

Table 36    Network Resiliency

Slogan

Limits

Self-healing network

The network solution is self-healing, including network fault detection and automated failover.

4.4.3   Tenant Network Limitations

Limitations of the tenant network are listed in Table 37.

Table 37    Tenant Network Limitations

Slogan

Limits

Number of virtual networks

The theoretical aggregated maximum number of virtual tenant networks per CEE region is 4050. Since each Neutron network created consumes RAM in the vCIC, this theoretical maximum cannot be reached. The default configuration of RAM for vCIC allows 1000 networks. Additional memory is needed if more Neutron Networks are created.


For rough estimations, consider that 100 Neutron networks with 1 subnet and 1 port for each cost about 2 GiB memory.

Number of vNICs per guest VM

The maximum number of vNICs per guest VM is 10 (+ 1 Trunk vNIC).

Number of Trunk vNIC attached vLANs

The number of Trunk vNIC attached vLANs is limited to 100.

Number of vNICs per blade

CSS supports up to 128 vNICs per Compute host.

L2 Packet MTU

The L2 Packet MTU size is 2140 bytes for the BSP internal network. Jumbo frames are not supported on the external network due to limitations in CMX.

4.5   Storage

This section describes CEE characteristics on storage.

4.5.1   Limitations

On BSP, the supported storage solutions are local storage and distributed storage.

For tenants, ephemeral storage (non-persistent block storage) is supported on local disks of the compute hosts. Persistent block storage is not supported on BSP systems.

There is no support for any shared file system in CEE. For distributed storage, see separate sections.

Swift uses the local storage, and Swift is also supported on distributed storage ScaleIO.

Object storage through Swift is only used for the CEE infrastructure.

Management of VM images is supported by the OpenStack image service.

Only boot from image is supported for BSP.

Table 38 shows where data is stored.

Table 38    Storage Locations

Data

Storage Location

CEE infrastructure backups (incl. Fuel backups)

On local disks of vCIC hosts(1)

Ephemeral storage

On local disks of Compute hosts (1)

vCIC storage (OpenStack infrastructure)

On local disks of vCIC hosts (1)

Core/crash dumps, logs

On local disks of all hosts

(1)  Local storage is limited by the local, non-scalable disk capacity.


Data is stored on a local disk, and it is erased in case of disk failure or rollback from a failed update, meaning that the VM disappears. The application must be designed accordingly.

4.5.2   VM Migration with NoMigration Policy Set

When a VM has No Migration policy set and is booted from local storage, it will not be started again after a rollback since the /var/lib/nova partition is not preserved.

The ephemeral disk for the VM is stored on local disk of the compute node. If the compute node must be replaced (because of, for instance, HW failure), any change in the VM is lost.

Boot from Volume is not available in BSP configurations.

4.5.3   Resiliency

Storage resiliency characteristics are listed in Table 39.

Table 39    Storage Resiliency

Slogan

Characteristics

Swift storage resiliency

Swift storage is replicated over the local disks that run vCIC.(1)

(1)  Glance uses Swift.


4.6   In-Service Performance

This section lists the characteristics on in-service performance.

Table 40    In-Service Performance

Slogan

Characteristics

Guest execution retainability

Guest execution is not interrupted at a virtual Infrastructure management cluster restart or update.

Update availability

When the update is running, OpenStack API is unavailable for about a minute for each CIC node. During rollback, negative response is occasionally returned.

Restart availability

It is not possible to connect to the API during the restart. The applications are designed to handle this and will not time out during restart.

5   System Limitations

This section describes the system limitations in R6.

5.1   OpenStack Deviations

The major deviations from the OpenStack SW are:

See relevant API descriptions for more information about limitations.

Limitations, Listed in API Documents

See the following API documents for more information on limitations:

5.2   SW Configurations and Options

This section describes SW configurations and options.

5.2.1   Allocation of Memory

CEE supports flavors that allocate VM memory aligned to n × 1 GiB memory when hugepages are enabled. There is a Nova patch that makes Nova aware of this. The hugepages are in chunks of 1 GiB memory, all of which is reserved to the VM even if less memory is asked for.

Each Neutron network created consumes RAM in the vCIC, and it influences the maximum number of virtual tenant networks. See Section 4.4.3 for more information.

5.2.2   Allocation of vCPU

The vCPU is limited to even number of vCPUs, see Section 4.1.

5.2.3   Collocation of vCIC, vFuel, and Atlas

Only two of the following can be run on the same Compute host: vCIC, vFuel, Atlas.

5.2.4   Number of Parallel Root Volume Operations

Nova in CEE supports about 500 parallel stop/detach root volume operations.

5.3   Not Supported

This section describes functionalities that are not supported. These are included here because they are not related to any specific configurations.

5.3.1   Dashboard Does Not Support Internet Explorer

The Dashboard does not support Internet Explorer because of the Ericsson Graphical User Interface (GUI) Software Development Kit (SDK).

5.4   Limitations and Workarounds

CM-HA operates in active-passive mode. If a Compute host containing a vCIC that runs the active CM-HA restars, the VM evacuation will not start within one minute. The evacuation only starts when the CM-HA process is moved to another vCIC by Corosync, and the Compute unavailability is detected by the CM-HA.

5.5   Update Limitations

OpenStack API is not always available during update and rollback. When the update is running, the OpenStack API is unavailable for about a minute for each CIC node. During rollback, a negative response is occasionally returned. For more information, see Section 4.6.

5.6   Hardware Platform Limitations

This section describes the limitations for Ericsson Blade Server Platform (BSP).

CEE R6 has the following limitations:

Table 41    Supported Hardware

Item

Status

Servers

BSP(1)

EBS with the following:


  • ROJ 208 866/5, GEP5-64G

  • ROJ 208 868/5, GEP5-64-400

  • ROJ 208 867/5, GEP5-64-1200

  • ROJ 208 841/7, GEP7-128-X

  • ROJ 208 844/7, GEP7-128-X16

  • SCXB3 – ROJ 208 395/1(2)

  • CMXB3 – ROJ 208 392/1 (2)

(1)  BSP means fimware + BIOS.

(2)  CEE supports the hardware versions of the board that are supported by BSP. For more information, refer to BSP Hardware Baseline, Reference [3].



Reference List

[1] BSP Technical Product Description, 221 02-FGC 101 2255
[2] Juniper Networks homepage, www.juniper.net
[3] BSP Hardware Baseline, 1090-CRA 119 1772, available at Ericsson Support


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