EMC ViPR Support for Stretched Host Clusters

Table of Contents

Back to Top

ViPR limitations with stretched host clusters in VPLEX environments

EMC ViPR supports stretched host clusters in VPLEX environments. However, ViPR 2.0 has limitations in the presence of stretched host clusters. This article describes those limitations, and any applicable work-arounds.

This article describes two data center configurations:
  • Stretched host clusters in a VPLEX Metro environment with fabrics stretched across data centers.
  • Stretched host clusters in a VPLEX Metro environment with fabrics isolated within data centers.
Back to Top

Data center description - stretched host cluster with isolated fabric

Exports to a stretched host cluster fail if the environment includes a VPLEX Metro server and isolated fabrics.

The following figure shows a physical data center that has the following features:
  • Two physical data centers.
  • A VPLEX Metro with a cluster in each data center.
  • Isolated fabrics.
  • Stretched host cluster. Nodes in the cluster exist in both physical data centers.
  • Two virtual arrays: one for each physical data center.

Exports of storage to the host cluster fail, because the host nodes in the virtual array for Data Center 2 cannot access the VPLEX virtual storage in Data Center 1.

Back to Top

Stretched host cluster with isolated fabric - workaround

This section describes one possible work-around to the export failure described in Stretched Host Cluster with Isolated Fabric. Use this procedure to restructure your host cluster so that ViPR can successfully export storage to your hosts.
  1. Create two host clusters in ViPR. In the first cluster, add hosts that have a physical connection to the VPLEX cluster in Data Center 1. In the second cluster, add hosts that have a physical connection the VPLEX cluster in Data Center 2.
  2. From the ViPR service catalog, run Block Storage Services > Create Block Volume for a host to create the distributed virtual volume from the VPLEX in site one and export it to the cluster nodes in site one.
  3. Run the ViPR service Block Protection Services > Export VPLEX Volume to export the distributed virtual volume from the VPLEX in site two to the cluster nodes in site two.

The following figure shows the result of the workaround.

stretched host cluster with isolated fabric workaround

Back to Top

Data center description - stretched host cluster with stretched fabric

ViPR supports exports to a stretched host cluster if the environment includes a VPLEX Metro server and a stretched fabric. To export storage to the hosts in both data centers from both VPLEX clusters, you must run two ViPR services.

The following figure shows an example data center with the following characteristics:
  • Two physical data centers.
  • A VPLEX Metro with a cluster in each data center.
  • Stretched fabric that spans both physical data centers.
  • Stretched host cluster. Nodes in the cluster exist in both physical data centers.
  • Two ViPR virtual arrays - one for each physical data center.

stretched host cluster with stretched fabric

Back to Top

Export storage to a stretched host cluster with stretched fabric

To provision VPLEX virtual volumes to all cluster nodes from both VPLEX arrays, run two services: one service for virtual array 1 (which includes elements in Data Center 1) and one service for virtual array 2 (which includes elements in Data Center 2).

Before you begin

The following procedure applies to the data center configuration described in Data Center Description - Stretched Host Cluster with Stretched Fabric.

To export a VPLEX Metro virtual volume to a host, run Block Protection Services > Export Volume to a Host.

You cannot use ViPR to export to hosts from two virtual arrays simultaneously. To accomplish this task, write a script with either the ViPR CLI or the ViPR REST API .

For more information about how to export a VPLEX Metro volume to a cluster, see Export a VPLEX Metro Virtual Volume To a Host or Cluster.

Procedure

  1. To create the distributed virtual volume from the VPLEX in Data Center 1 and export it to the cluster nodes on both sites, run the service Block Storage Services > Create Block Volume for a Host.
  2. To export the distributed virtual volume from the virtual array in Data Center 2 to the cluster nodes on both sites, run the service Block Storage Services > Export VPLEX Volume.