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ONTAP SAN hosts and cloud clients

Use Windows Server 2012 R2 with ONTAP

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You can use the ONTAP SAN host configuration settings to configure Windows server 2012 R2 for operation with ONTAP storage.

Boot the Windows OS

You can boot the Windows OS using a local boot or a SAN boot. NetApp recommends using a SAN boot if it is supported by your configuration.

Local boot

Perform a local boot by installing the Windows OS on the local hard disk (SSD, SATA, RAID, and so on).

SAN boot

If you choose to use SAN booting, it must be supported by your configuration.

Note You can use the configuration settings provided in this procedure to configure cloud clients connected to Cloud Volumes ONTAP and Amazon FSx for ONTAP.
Before you begin

Use the Interoperability Matrix Tool to verify that your Windows OS, host bus adapter (HBA), HBA firmware, HBA boot BIOS, and ONTAP version support SAN booting.

Steps

  1. Map the SAN boot LUN to the host.

    See SAN storage management.

  2. Verify that multiple paths are available.

    Note Multiple paths only become available after the host OS is up and running on the paths.

  3. Enable SAN booting in the server BIOS for the ports to which the SAN boot LUN is mapped.

    For information on how to enable the HBA BIOS, see your vendor-specific documentation.

  4. Reboot the host to verify the boot was successful

Install Windows hotfixes

NetApp recommends installing the latest cumulative update available from the Microsoft Update Catalog on the host server.

Steps

  1. Download the hotfixes from the Microsoft Update Catalog 2012 R2.

Note You need to contact Microsoft support for the hotfixes that aren't available for download from the Microsoft Update Catalog.

  1. Follow the instructions provided by Microsoft to install the hotfixes.

Tip Many hotfixes require a reboot of your Windows host. You can choose to wait to reboot the host until after you install or upgrade the Host Utilities.

Install the Windows Host Utilities

The Windows Host Utilities are a set of software programs with documentation that enables you to connect host computers to virtual disks (LUNs) on a NetApp SAN. NetApp recommends downloading and installing the latest utility kit. For Windows Host Utilities configuration information and instructions, see the Windows Host Utilities documentation and select the installation procedure for your Windows Host Utilities version.

Multipathing

You need to install the Microsoft Multipath I/O (MPIO) software and enable multipathing if your Windows host has more than one path to the storage system. When you select MPIO support, the Windows Host Utilities enables the MPIO feature included in Windows Server 2012 R2. If you're not using the Windows Host Utilities, you need to enable multipathing manually.

The MPIO software presents a single disk to the Windows OS for all paths, and a device-specific module (DSM) manages path failover. On a Windows system, the two main components in any MPIO solution are the DSM and the Windows MPIO.

Caution If you don't install the MPIO software, the Windows OS might see each path as a separate disk. This can lead to data corruption.
Note Windows XP or Windows Vista running in a Hyper-V virtual machine doesn't support MPIO.

SAN configuration

Depending on your SAN configuration, the host uses All SAN Array (ASA) or non-ASA configurations to access ONTAP LUNs. In both ASA and non-ASA configurations, you shouldn't require more than four paths to access a single ONTAP LUN. If you have more than four paths, it might cause issues with the paths during a storage failure.

All SAN array configuration

An ASA configuration should have one group of Active/Optimized paths with single priorities. This means the paths are serviced by the controller and the I/O is sent on all the active paths.

The following example displays the correct output for an ONTAP LUN with Active/Optimized paths.

Screenshot of ONTAP LUN with active/optimized paths

Non-ASA configuration

A non-ASA configuration should have two groups of paths with different priorities. The paths with higher priorities are Active/Optimized. This means the Active/Optimized paths are serviced by the controller where the aggregate is located. The paths with lower priorities are active but non-optimized because they are served from a different controller. The non-optimized paths are only used when optimized paths aren't available.

The following example displays the correct output for an ONTAP LUN with two Active/Optimized paths and two Active/Non-Optimized paths.

Screenshot of an ONTAP LUN with two active/optimized paths and two active/non-optimized paths

Hyper-V VHD requires alignment for best performance

If the data block boundaries of a disk partition don't align with the block boundaries of the underlying LUN, the storage system often has to complete two block reads or writes for every operating system block read or write. The additional block reads and writes caused by the misalignment might create serious performance problems.

The location of the starting sector for each partition defined by the master boot record causes misalignment.

Note Partitions created by Windows Server 2016 should be aligned by default.

Use the Get-NaVirtualDiskAlignment cmdlet in the ONTAP PowerShell Toolkit to check whether partitions are aligned with underlying LUNs. If the partitions are incorrectly aligned, use the Repair-NaVirtualDiskAlignment cmdlet to create a new VHD file with the correct alignment. This cmdlet copies all of the partitions to the new file. The original VHD file is not modified or deleted. The virtual machine must be shut down while the data is copied.

You can download the ONTAP PowerShell Toolkit at NetApp Communities. You must unzip the DataONTAP.zip file into the location specified by the environment variable %PSModulePath% (or use the Install.ps1 script to do it for you). After you have completed the installation, use the Show-NaHelp cmdlet to get help for the cmdlets.

The PowerShell Toolkit supports only fixed-size VHD files with MBR-type partitions. VHDs using Windows dynamic disks or GPT partitions aren't supported. In addition, the PowerShell Toolkit requires a minimum partition size of 4GB. Smaller partitions cannot be correctly aligned.

Note For Linux virtual machines using the GRUB boot loader on a VHD, you need to update the boot configuration after running the PowerShell Toolkit.

Reinstall GRUB for Linux guests after correcting MBR alignment with PowerShell Toolkit

After running mbralign on disks for correcting MBR alignment with PowerShell Toolkit on Linux guest operating systems using the GRUB boot loader, you must reinstall GRUB to ensure that the guest operating system boots correctly.

About this task

The PowerShell Toolkit cmdlet has completed on the VHD file for the virtual machine. This procedure applies only to Linux guest operating systems using the GRUB boot loader and SystemRescueCd.

Steps

  1. Mount the ISO image of Disk 1 of the installation CDs for the correct version of Linux for the virtual machine.

  2. Open the console for the virtual machine in Hyper-V Manager.

  3. If the VM is running and frozen at the GRUB screen, click in the display area to make sure it is active, then select the Ctrl-Alt-Delete toolbar icon to reboot the VM. If the VM is not running, start it, and then immediately click in the display area to make sure it is active.

  4. As soon as you see the VMware BIOS splash screen, press the Esc key once. The boot menu displays.

  5. At the boot menu, select CD-ROM.

  6. At the Linux boot screen, enter: linux rescue

  7. Take the defaults for Anaconda (the blue/red configuration screens). Networking is optional.

  8. Launch GRUB by entering: grub

  9. If there is only one virtual disk in this VM, or if there are multiple disks and the first is the boot disk, run the following GRUB commands:

    root (hd0,0)
setup (hd0)
quit

    If you have multiple virtual disks in the VM, and the boot disk isn't the first disk, or you are fixing GRUB by booting from the misaligned backup VHD, enter the following command to identify the boot disk:

    find /boot/grub/stage1

    Then run the following commands:

    root (boot_disk,0)
setup (boot_disk)
quit
    Note In setup (boot_disk), boot_disk is a placeholder for the actual disk identifier of the boot disk.

  1. Press Ctrl-D to log out.

    Linux rescue shuts down and then reboots.

When you select MPIO on systems using FC, the Host Utilities installer sets the required timeout values for Emulex and QLogic FC HBAs.

Emulex FC

The timeout values for Emulex FC HBAs:

Property type Property value

LinkTimeOut

1

NodeTimeOut

10
QLogic FC

The timeout values for QLogic FC HBAs:

Property type Property value

LinkDownTimeOut

1

PortDownRetryCount

10
Note For more information on the recommended settings, see Configure registry settings for Windows Host Utilities.

Known issues

There are no known issues for the Windows Server 2012 R2 with ONTAP release.