• Setting up a host to use Unity VMware VMFS iSCSI datastores

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    Setting up a host to use Unity VMware VMFS iSCSI datastores

    Requirements for setting up a host to use Unity VMware VMFS datastores

    Before you set up a host to use Unity VMware VMFS datastores, these storage system and host and network requirements must be met.

    iSCSI network requirements for host connection to VMFS datastores

    For a host to connect to VMware VMFS datastores on a Unity iSCSI interface, the host must be in a network environment as the iSCSI interface. To achieve best performance, the host should be on a local subnet with each Unity iSCSI interface that provides storage. For a Windows multi-pathing environment, each Unity iSCSI interface providing iSCSI LUNs for the host must have two IP addresses associated with it. These two addresses should be on different subnets to ensure high availability. If possible, you should segment network traffic from the Unity system through a private LAN using either a virtual LAN or a dedicated network switch.

    To achieve maximum throughput, connect the Unity iSCSI interface and the hosts for which it provides storage to their own dedicated private network. Consider network performance when choosing the network.

    Path management network requirements for VMFS datastores

    When implementing a highly-available network between a host and the Unity system, keep in mind that:

    • You can configure up to 32 IPs/VLANs per physical interface. You can create up to 64 iSCSI IPs per system.
    • Network switches may be on separate subnets.
    Note:  Directly attaching an ESX host to a Unity system is supported.

    The following figure shows a highly-available iSCSI network configuration for hosts accessing a Unity storage resource (VMware VMFS datastore). Switch A and Switch B are on separate subnets. Host A and Host B can each access the storage resource through separate NICs. If the storage resource is owned by SP A, the hosts can access the storage resource through the paths to the eth2 interface on SP A. Should SP A fail, the Unity system transfers ownership of the resource to SP B and the hosts can access the storage resource through the paths to the eth2 interface on SP B.

    Figure 1. Highly-available iSCSI network example
    Highly-available iSCSI network example

    Using multi-path management software with ESXi hosts

    Multi-path management software manages the connections (paths) between the host and the Unity system to provide access to the Unity storage should one of the paths fail. The following types of multi-path management software are available for an ESXi host connected to a Unity system:

    • ESXi native failover on any ESXi host
    • EMC PowerPath/VE software on an ESXi 5.x or later host

    For the supported versions of the PowerPath/VE software, refer to the Unity Support Matrix on the support website.

    Setting up your system for multi-path management software

    For your system to operate with hosts running multi-path management software, two iSCSI IPs are required. These IPs should be on separate physical interfaces on separate SPs.

    Verify the configuration in Unisphere. For details on how to configure iSCSI interfaces, refer to topics about iSCSI interfaces in the Unisphere online help.

    Note:  For highest availability, use two network interfaces on the iSCSI interface. The network interfaces should be on separate subnets. You can view the network interfaces for an iSCSI interface within Unisphere.

    Installing PowerPath

    Procedure
    1. On the host or virtual machine, download the latest PowerPath version from the PowerPath software downloads section on the Online Support website.
    2. Install PowerPath as described in the appropriate PowerPath installation and administration guide for the host’s or virtual machine’s operating system.
      This guide is available on Online Support. If the host or virtual machine is running the most recent version and a patch exists for this version, install it, as described in the readme file that accompanies the patch.
    3. When the installation is complete, reboot the host or virtual machine.
    4. When the host or virtual machine is back up, verify that the PowerPath service has started.

    Configuring the ESXi iSCSI adapters

    Follow these steps to configure software iSCSI adapters. If CHAP authentication is required, follow VMware vSphere documentation to configure CHAP parameters for iSCSI adapters.
    Procedure
    1. Log into VMware vSphere Client as administrator.
    2. From the Inventory panel, select the server with the initiator that you want to configure.
    3. Click the Configuration tab, and click Storage Adapters.
    4. Click Add in the Add Storage Adapter dialog box, and then select Add Software iSCSI Adapter.
    5. Select the iSCSI initiator that you want to configure, and click Properties.
    6. In the iSCSI Initiator Properties page, click the General tab and then click Configure.
    7. Select Enabled.
    8. Under iSCSI Properties, enter a user-friendly iSCSI name and an iSCSI alias for the software iSCSI initiator, and then click OK.
    9. [Generic host objects only] Add target addresses for the software iSCSI initiator:
      1. Click the Static Discovery tab and click Add.
      2. Add the target’s information and click OK.
      3. Rescan the adapter.
    10. If you want to configure CHAP credentials for the target, access the iSCSI Initiator Properties page, click the Static Discovery tab, and click Settings > CHAP. Then rescan the adapter.

    Creating a VMkernel port for the software iSCSI adapter

    Connect the VMkernel, which runs services for iSCSI storage, to the physical network adapter.
    Procedure
    1. Log in to the vSphere Client as an administrator.
    2. From the Inventory panel, select the host.
    3. Click the Configuration tab, and click Networking.
    4. In the Virtual Switch view, click Add Networking.
    5. Select VMkernel and click Next.
    6. Select Create a virtual switch to create a new vSwitch.
    7. Select an adapter that you want to use for iSCSI traffic and click Next.
      Note:  Do not use iSCSI on 100 Mbps or slower adapters.
      If no adapters appear under Create a virtual switch, the existing vSwitches are using all the network adapter in the host. In this situation, you can use an existing vSwitch for iSCSI traffic.
    8. Under Port Group Properties, enter the network label, and click Next.
      The network label is the name that you want to identify the VMkernel port that you are creating.
    9. Specify the IP settings and click Next.
    10. After you review the summary information, click Finish.
    After you finish

    If your host uses only one physical network adapter for iSCSI, your network configuration is complete.

    If your host uses more than one physical network adapter for iSCSI, you must connect additional adapters to the vSwitch and associate each port with a VMkernel port using the port binding technique. You can do this in one of following ways:

    • Create separate vSwitches for each additional network adapter by repeating the above steps for each additional adapter.
    • Use a single vSwitch for iSCSI multipathing by connecting the additional network adapters and VMkernel ports to the vSwitch that you just created and override the default setup so that each port maps to only one active adapter.

    Setting up multipathing for iSCSI

    Before you begin

    Use this procedure only if both of these conditions are met:

    • You want to connect all of these iSCSI NICs to a single vSwitch.
    • You have two or more NICs that you can designate for iSCSI.

    Before following the procedure below to set up multipathing for software iSCSI, you must have created one VMkernel port for your network adapter.

    NOTICE  If the network adapter that you add to the software iSCSI initiator is not in the same subnet as your iSCSI target (iSCSI interface), the host cannot establish sessions from this network adapter to the target.
    The procedure associates VMkernel ports with the iSCSI NICs using a 1-to-1 mapping.
    Procedure
    1. Log in to the vSphere Client as an administrator.
    2. From the Inventory panel, select the host.
    3. Click the Configuration tab, and click Networking.
    4. Select the vSwitch that you use for iSCSI and click Properties.
    5. Bind additional network adapters to the vSwitch:
      1. In the vSwitch Properties dialog box, click the Network Adapters tab and click Add.
      2. From the list of adapters, select the ones that you want to add to the vSwitch and click Next.
      3. After you review the information on the summary page, click Finish.
        The list of network adapters reappears, showing the network adapters that the vSwitch claims.
    6. Create VMkernel ports for that network adapters that you connected to the vSwitch:
      Note:  Each VMkernel port in a vSwitch with multiple network adapters must have only one network adapter designated as active for each VMkernel port. The other adapters must be designated as unused.
      1. In the vSwitch Properties dialog box, click the Ports tab and click Add.
      2. Select VMkernel and click Next.
      3. Under Port Group Properties, enter a network label and click Next.
        The network label is the name that you want to identify the VMkernel port group that you are creating.
      4. Specify the IP settings and click Next. When you enter the subnet mask, be sure that the network adapter is set to the subnet of the iSCSI interface to which it connects.
      5. After you review the information on the summary page, click Finish.
    7. Map each VMkernel port to just one active adapter.
      By default all network adapters appear as active for each VMkernel on the vSwitch. You must override this setup so that each port maps to only one active adapter. For example, VMkernel port vmk1 maps to active adapter vmnic1, port vmk2 maps to vmnic2, and so on.

      For each VMkernel port on the vSwitch:

      1. On the Ports tab, select a VMkernel port and click Edit.
      2. Click the NIC Teaming tab and select Override vSwitch failover order.
      3. Specify only one adapter as active and move all the remaining adapters to the Unused Adapters list.
    8. Connect the VMkernel ports to the software iSCSI initiator:
      1. Log in to the vSphere client as an administrator.
      2. From the Inventory panel, select the host.
      3. Click the Configuration tab, and click Storage Adapters.
      4. Select the iSCSI adapter and click Properties.
      5. Select the Network Configuration tab and click Select.
      6. Select the VMkernel ports on the vSwitch and then click OK.
      7. Review the summary and click Finish.

    Configuring the Unity VMware VMFS datastores for the host

    Procedure
    1. Add the software iSCSI adapter, if not already added, as described in VMware vSphere documentation.
    2. Use Unisphere UI or CLI to:
      1. Discover VMware ESXi hosts.
      2. Create Unity VMFS datastores.
      For more information about completing these tasks, refer to the Unisphere online help or the Unisphere CLI User Guide.
      Note:  When you create Unity VMFS datastores for discovered VMware ESXi hosts, the system automatically configures the hosts to use the datastores. If you select multiple discovered hosts for the datastores, all the selected hosts are configured automatically. The VMware VMFS datastores are presented directly to the ESXi hosts and not to the hosts’ virtual machines. If an ESXi host cannot see the VMFS datastore after you create the datastore, manually configure the connection to the VMFS datastore.
    3. Rescan for the VMFS datastores:
      1. From the Hosts and Clusters panel, select the server.
      2. Select Manage.
      3. Under Storage, select Storage Adapters.
        1. Select the iSCSI storage adapter in the list of adapters.
        2. Select the Rescan icon.
      4. Under Storage, select Storage Devices.
      5. Select the Rescan icon.

      If the host can see the VMFS datastore, you must set up the host to use the datastore, as described in the next section.

      If the host cannot see the VMFS datastore, you may have a problem with the connection between the host and iSCSI target (iSCSI connection). Refer to iSCSI session troubleshooting for ESXi hosts for additional steps to resolve the problem.

    Configuring ESXi host native failover

    ESXi hosts include native failover for managing the I/O paths between the server and storage system. Native failover provides multiple paths from the server to the storage system. To use ESXi host native failover with your storage system, you must implement one of the failover policies listed below. For more information about these policies, refer to VMware ESXi configuration documentation.

    • Round Robin (default)
    • Fixed with failover mode
    • Most Recently Used (MRU)

    Configuring the native failover policy for iSCSI connections

    Procedure
    1. Log into the vSphere client as administrator.
    2. From the Inventory panel, select the server, and click the Configuration tab.
    3. Under Hardware, click Storage and select the datastore (LUN).
    4. Click Properties.
    5. In the Properties page, click Manage Paths.
    6. In the Manage Paths page, under Policy, verify that the policy is one you want:
      • Fixed (VMware) for fixed native failover policy
      • Round Robin (VMware) for Round Robin native failover policy
      • Most Recently Used (VMware) for MRU native failover policy
      If the policy is not set to the desired policy, in the policy selection dialog, select the correct policy.
    7. If you selected the Fixed (VMware) policy, under Paths, select the preferred path.
      You can statically balance the load using the fixed policy by selecting different paths for each datastore. To designate a different path as preferred, right click on the path and click preferred.
    8. Click Close.
    After you finish

    You are now ready to either migrate a virtual machine to the VMFS datastore or create a virtual machine on the VMFS datastore. To migrate a virtual disk to the VMFS datastore, see the section on Migrating VMware Virtual Machines to the Unity System. For information about creating a virtual machine on the VMFS datastore, refer to the VMware documentation.

    A rescan of the storage is required after any change is made to the SAN.

    Manually setting up the iSCSI connection for a Unity VMFS datastore

    If you want to use generic host objects, you must manually add the software iSCSI adapter:
    Procedure
    1. Log in to the vSphere Client as an administrator.
    2. From the Inventory panel, select the host with the initiator you want to configure.
    3. Click the Configuration tab, and click Storage Adapters.
    4. If the Software iSCSI adapter is not listed, click Add in the Add Storage Adapter dialog box, and then select Add Software iSCSI Adapter.
    5. Select the iSCSI initiator that you want to configure, and click Properties.
    6. In the iSCSI Initiator Properties page, click the General tab and then click Configure.
    7. If the adapter is not already enabled, select Enabled.
    8. If you want a name and alias for the software iSCSI adapter, enter them under iSCSI Initiator Properties and click OK.

    Manually setting up the connection to a Unity iSCSI VMFS datastore

    Procedure
    1. Log in to the vSphere client as an administrator.
    2. Rescan for new storage devices:
      1. From the Inventory panel, select the server, and click the Configuration tab.
      2. Verify that the iSCSI adapter is in the vSphere static discovery table.
        1. Select the Manage tab, then select Storage.
        2. Under Adapter Details, select Targets and Static Discovery.
        3. Verify that the storage system iSCSI adapter information appears.
      3. Under Hardware, click Storage Adapters.
        1. Under iSCSI Software Adapters in the list of adapters, select the adapter (NIC), and then click Rescan.
        2. In the Rescan dialog box, select the adapter (NIC), and then click Rescan.
      4. In the Rescan dialog box, select both Scan for New Storage Devices and Scan for New VMFS Volumes, and click OK.
    3. Add each VMFS datastore to the ESXi host:
      1. From the Inventory panel, select the host and click the Configuration tab.
      2. Under Hardware, click Storage, and click Add Storage.
      3. On the Select Disk/LUN page, select the Unity VMFS datastore that you want to use for the datastore, and click Next.
      4. On the Current Disk Layout page, review the current virtual disk layout, and click Next.
      5. On the Disk/LUN-Properties page, enter the exact same name that was used to create the datastore on the storage system.
        You can find this name using Unisphere.
      6. On the Disk/LUN-Formatting page, if needed, adjust the file system values and the capacity for the datastore, and click Next.
      7. On the Ready to Complete page, review the datastore information, and click Finish
    Results
    The datastore (VMFS volume) is created on the Unity VMFS datastore for the ESXi host.

    iSCSI session troubleshooting for ESXi hosts

    Verify the connectivity between the host and the target either from the storage system iSCSI interface IP interface or from the ESXi host:
    Procedure
    1. Verify the connectivity between the host and the target either from the Unity iSCSI interface IP interface or from the ESXi host:
      From the iSCSI IP interface:
      1. Select the Settings icon, then select Access > Routing.
      2. Select the iSCSI interface and select Ping/Trace.
      3. Enter the network name of the host iSCSI adapter, select the IP address from which to send the request, and click Ping.
      From the ESXi host:
      1. Use vmkping to verify connectivity to the Unity iSCSI interface IP interfaces.
      2. If jumbo frames are configured, you should use vmkping with the -s option at a size larger than 1500 to verify that all network elements are properly configured for jumbo frames.
        vmkping -s 9000 <IP_address_of_iSCSI _Server>
        Using the IP address avoids name resolution issues.
        Note:  You can find the IP address for the target by selecting Settings > iSCSI Settings in Unisphere.
      Some switches intentionally drop ping packets or lower their priority during times of high workload. If the ping testing fails when network traffic is heavy, verify the switch settings to ensure the ping testing is valid.
    2. On the host, verify that the iSCSI adapter has been added.
      Note:  The iSCSI service on the iSCSI interface starts in vSphere when the storage system is powered up.
    3. If you are using CHAP authentication, ensure that the CHAP security settings are correct for your system. See VMware vSphere steps for configuring CHAP parameters for iSCSI adapters.