Many RHEV shops prefer a shared-storage configuration for a variety of reasons, including increased uptime and mobility. If expense is not an issue, connecting an iSCSI SAN to RHEV is a straighforward process.
Adding storage to a Red Hat Enterprise Virtualization (RHEV) environment is part of a longer procedure: You first set up the RHEV environment and the RHEV-M console as add RHEV-H hosts to the management console. The next step is to connect the shared storage to the RHEV infrastructure.
Adding the shared-storage network to RHEV
To assign shared-storage to a RHEV environment, you must first configure the data center and create a storage network. If you have not set up a custom data center, you will have one with the name Default. In RHEV-M, it appears directly under the System object. Select the Default data center to see its properties in the lower part of the window.
At the moment, there’s only the management network. To add a new network for storage traffic, click Add and enter the parameters for this network (e.g., a name and description). Next, click OK to assign this network to the data center, which will function as the storage network.
After you create a new shared-storage network, the RHEV hosts need to access it. To do this, select the host you want to assign to the network from the lower part of the management window. Then, click Network Interfaces, which displays the network interfaces that are currently available. At this point, you should see only one interface, which is assigned to the management network. From this list, select the interface you want to assign to the shared-storage network.
Creating the new data store
At this point, you can set up the new data store. At the data center level, assign individual hosts to the newly created shared-storage network. In RHEV, you can use three kinds of shared storage: Network File System (NFS), iSCSI or Fibre Channel. In this example, you’ll first set up an iSCSI storage domain.
To do this, from the Data Center Storage tab, click New Domain. Next, a new window opens, where you can select the default storage type that you assigned during the RHEV-M installation. With iSCSI, you must enter the required properties to connect to the iSCSI SAN, which may be simply an IP address for the iSCSI host.
Once you enter the address, click Discover to see all of the available iSCSI targets. From this list, click Login on a target. If successful, you are now connected to the iSCSI shared storage, and you will see all of the logical unit numbers (LUNs) available from that target. Select a LUN and click OK to make this storage available to the RHEV hosts.
Populating the ISO storage domain
At this point, you’ve connected the RHEV data center to iSCSI shared storage. During the installation, you probably indicated a location for ISO storage. It is important to configure the ISO storage and that it’s available to the data center, so that you can install virtual machines later.
To make the ISO storage domain available to the data center, select the default data center. On the storage tab, click Attach ISO. You can now use both storage domains on the hosts in your RHEV environment.