Configure the multipath software

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 ThinkSystem Storage Manager is a deprecated application, it is important that if you uninstall ThinkSystem Storage Manager, you do not uninstall the DSM. MPIO must be installed prior to installing the DSM for MPIO to work properly.

For Linux and Windows Hyper-V environments, you will need to make additional changes.

• Linux 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 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.