Deploying a Metro Storage Cluster across two sites using Huawei OceanStor Pacific HyperMetro and VMware vSphere

Products

• VMware vSphere ESXi

Issue/Introduction

Purpose

This article provides information about deploying Metro Storage Cluster across two sites using HyperMetro feature of Huawei OceanStor Pacific distributed storage system and VMware vSphere platform.

Minimum Requirements

The minimum system requirements for Huawei OceanStor Pacific to support vMSC solution with HyperMetro are as follows:

• Only iSCSI Protocol is supported to connect Huawei OceanStor Pacific Storage System to ESXi hosts.
• Huawei OceanStor Pacific storage system with version 8.0 or newer.
• VMware ESXi 6.0 and later version with VMware NMP.
• When ALUA feature is enabled on OceanStor Pacific storage system, the VMW_SATP_ALUA SATP policy must be configured on all ESXi hosts.
• Support Host access in uniform (recommended) topology or non-uniform topology

Environment

VMware ESXi 6.7.x
VMware ESXi 6.0.x
VMware ESXi 5.0.x
VMware vSphere ESXi 7.0.x
VMware ESXi 6.5.x

Resolution

Resolution

Huawei OceanStor Pacific and HyperMetro

Huawei OceanStor Pacific features elastic scalability, superb performance, robust reliability, solid security, enhanced data protection, outstanding intelligence, efficiency, and cost-effectiveness, high usability, and wide compatibility. It has multiple data protection features, including HyperMetro, HyperReplication, HyperSnap, and HyperClone, as well as a variety of features to improve space utilization and performance, such as SmartDedupe, SmartCompression, SmartThin (thin provisioning), SmartQoS (Quality of Service), and SmartCache (caching). It is compatible with various virtualization platforms and applications.
HyperMetro delivers active-active read/write capabilities using two OceanStor Pacific clusters. If one data center fails, the system automatically switches to the other cluster to ensure service continuity.

Solution Overview:

Figure 1 - HyperMetro Configurations for Huawei OceanStor Pacific Storage System




Huawei HyperMetro storage cluster provides the following capabilities: 

• Two OceanStor Pacific storage systems on two sites can both be Readable/Writable to all ESXi hosts. 
• HyperMetro pairs can work in active-active mode (VMW_SATP_DEFAULT_AA as SATP policy) and active-standby mode. In active-standby mode, VMW_SATP_ALUA as SATP policy must be configured for all ESXi hosts, in according with ALUA feature enabled on OceanStor Pacific storage system.

Arbitration server:

Two arbitration modes are provided by OceanStor Pacific storage system:

• Static priority mode: This mode is mainly used in scenarios where no third-party arbitration servers are deployed. In this mode, you can set either end as the preferred site based on active-active pairs or consistency groups and the other end the non-preferred site. 
• If the link between the storage arrays or the non-preferred site encounters a fault, LUNs at the preferred site are accessible, and those at the non-preferred site are inaccessible. 
• If the preferred site encounters a fault, the non-preferred site does not accessible to hosts.
• Arbitration server mode: In this mode, an independent physical or virtual machine is used as the arbitration device, which determines the type of failure, and uses the information to choose one side of the device pair to remain R/W accessible to the host. The Arbitration server mode is the default option.

Notes:

• The operating system’s support matrix with Huawei storage, please visit http://support-open.huawei.com/en/ for more details
• Arbitration server can be built on a physical or virtual machine.

For more details, please refer to the Restrictions notes with part number “OceanStor Pacific Series 8.1.0 Best Practices for Block (VMware vSphere, HyperMetro) 01” on Huawei Support.

Recommendations and Limitations:

It is recommended that the LUN mapping of second storage system to ESXi hosts starts only when the HyperMetro Pair is configured successfully. Then the rescan command can used to detect the new paths manually, or waiting for the automatically path detection provided by VMware NMP. 

Notes: There might be some delays in automatic path detection, please refer to the VMware KB article for instructions: Changing the polling time for datastore paths (1004378).

For more information on configuration guidelines, please refer to the latest OceanStor Pacific HyperMetro Configuration in VMware vSphere Scenarios.
A certified configuration of OceanStor Pacific storage system is available and listed in the VMware Compatibility Guide.

Tested Scenarios:

This table outlines the tested and supported failure scenarios when using the OceanStor Pacific Storage Cluster for VMware vSphere:

 

Scenario	Operation	Observed VMware behavior (uniform)	Observed VMware behavior (non-uniform)
Cross-data-center VM migration	Migrate a VM from site A to site B.	No impact.	No impact.
Physical server breakdown	Unplug the power supply for a host in site A.	VMware High Availability failover virtual machines to other available hosts.	VMware High Availability failover virtual machines to other available hosts.
Single-link failure of physical server	Unplug the physical link that connects a host in site A to an switch.	No impact.	No impact.
Storage failure in site A	Unplug the power supply for the storage system in site A.	No impact.	VMware High Availability failover virtual machines to available site B hosts.
All-link failure of storage in site A	Unplug all service links that connect site A's storage array to an switch.	No impact.	VMware High Availability failover virtual machines to available site B hosts.
All-link failure of all hosts in site A	Unplug all physical links that connect all hosts in site A to an switch.	VMware High Availability failover virtual machines to available site B hosts.	VMware High Availability failover virtual machines to available site B hosts.
Failure of storage replication links	Unplug replication links between sites.	No impact.	Virtual machines in site B hosts are automatically Powered off in site B hosts and Powered on in available site A hosts.(ps: The perfect site is site A)
Failure of storage management network	Unplug network cable from network port of host in site A.	No impact.	No impact.
All-link failure between sites	Disconnect the DWDM links between sites.	Virtual machines in site B hosts are automatically Powered off in site B hosts and Powered on in available site A hosts.(ps: The perfect site is site A)	Virtual machines in site B hosts are automatically Powered off in site B hosts and Powered on in available site A hosts.(ps: The perfect site is site A)
Failure of site A	Power off all devices in site A.	VMware High Availability failover virtual machines to available site B hosts.	VMware High Availability failover virtual machines to available site B hosts.
Failure of site B	Power off all devices in site B.	VMware High Availability failover virtual machines to available site A hosts.	VMware High Availability failover virtual machines to available site A hosts.