Configure the multipath software

Multipath software provides a redundant path to the storage array in case one of the physical paths is disrupted. Before you can use multipathing, you need to enable Windows Multipathing feature and the ThinkSystem Windows DSM package. This package contains the multipath software for Windows.

Windows installations use the native MPIO Device Specific Module (DSM) driver for failover. When you install ThinkSystem Storage Manager, the DSM driver is installed and enabled.

When installing the DSM for windows, you must first install MPIO through the Server Manager console. Once completed you must install the DSM by installing the ThinkSystem Storage Manager package. This package contains the DSM, the context agent, and the SMCLI. While Storage Manager is a deprecated application, it is important that if you uninstall Storage Manager, you don't uninstall the DSM. MPIO must be installed prior to installing the DSM for MPIO to work properly.

Parent topic: Windows express configuration

Install ThinkSystem Windows DSM package

Perform the following steps to install the ThinkSystem Windows DSM package and use the multipath package for Windows.

Before you begin

  • You must have the correct administrator or superuser privileges.

  • Enable the Multipathing Feature under PowerShell with administrator privilege and reboot: Add-WindowsFeature -Name 'Multipath-IO' -Restart

You will install the ThinkSystem Windows DSM package on the management station.

  1. Download the ThinkSystem Storage Manager package from DE Series Product Support Site Drivers&Software > Software and Utilities
  2. Run the ThinkSystem Storage Manager. Double-click the install package to execute.
  3. Use the installation wizard to install the package on the management station.

Hyper-V guest OS configuration

  • Linux guest OS under Hyper-V

    The \"udev\" facility is the best way to automatically configure disk timeouts when new disks are added to a VM and at boot time. A simple way to determine the VID /PID (Vendor ID/Product ID) of any disks currently added to the VM is to run the following command and look at the vendor and model information: cat /proc/scsi/scsi. In order to set this up, create the file /etc/udev/rules.d/99-msft-udev.rules with the following content: 
    ACTION=="add", 
SUBSYSTEMS=="scsi", 
ATTRS{vendor}=="LENOVO ", 
ATTRS{model}=="DE_Series", 
RUN+="/bin/sh -c 'echo 180 >/sys$DEVPATH/timeout'" 
ACTION=="add", 
SUBSYSTEMS=="scsi", 
ATTRS{vendor}=="Msft ", 
ATTRS{model}=="Virtual Disk ", 
RUN+="/bin/sh -c 'echo 180 >/sys$DEVPATH/timeout'"

    The vendor and model fields in the udev rules file have fixed-widths of 8 and 16 characters respectively. Note the additional white space padding in the example above. Once this file has been modified, you can either restart udev or reboot the VM to activate the changes.

  • Windows guest OS under Hyper-V

    In order to configure disk I/O timeouts for Windows Hyper-V environments, you must edit a single registry key:

    [HKEY_LOCAL_MACHINE\\SYSTEM\\CurrentControlSet\\Services\\Disk] 
\"TimeOutValue\"=dword:000000b4

    Once that's done, you must restart the VM for the changes to take effect.

For Linux and Windows guest OS under Hyper-V environment, you will need to make additional changes.