Dynamic Multi-Pathing 8.0.1 Administrator's Guide - Windows

Last Published:
Product(s): InfoScale & Storage Foundation (8.0.1)
Platform: Windows
  1. Understanding DMPW
    1.  
      DMP overview
    2.  
      Major features of Dynamic Multi-Pathing
    3. How DMP works
      1. How DMP monitors I/O on paths
        1.  
          Path failover mechanism
      2.  
        Load balancing
      3.  
        DMP in a clustered environment
    4.  
      Multiple paths to disk arrays
    5.  
      Device discovery
  2. Setting up DMPW
    1.  
      Active/Active and Active/Passive settings
    2. Active/Active and Active/Passive settings in a cluster environment
      1.  
        DMP DSMs
      2.  
        SCSI-3 PGR technology
      3.  
        Enabling SCSI-3 PGR
    3. Add and remove paths
      1.  
        Adding a path
      2.  
        Removing a path
    4. Specify load balancing settings and the primary path
      1.  
        Specifying load balancing settings for an array
      2.  
        Specifying load balancing settings for a disk
      3.  
        Specifying the primary path for an array or disk
    5. Configuring DSMs without storage connection
      1.  
        Specify DSM settings without storage connection
  3. Administering DMPW
    1.  
      About administering DMP
    2. DMP DSMs menus
      1.  
        Displaying the menu for arrays
      2.  
        Commands for arrays
      3.  
        Displaying the menu for disks
      4.  
        Commands for paths of a disk
      5.  
        Statistics monitoring
      6.  
        Clear performance statistics
      7.  
        Device settings
      8.  
        Set primary path
      9.  
        Properties
    3. View array, disk, and path status
      1.  
        Array status
      2.  
        Device status
      3.  
        Path status
    4. vxdmpadm
      1.  
        vxdmpadm dsminfo
      2.  
        vxdmpadm arrayinfo
      3.  
        vxdmpadm deviceinfo
      4.  
        vxdmpadm pathinfo
      5.  
        vxdmpadm arrayperf
      6.  
        vxdmpadm deviceperf
      7.  
        vxdmpadm pathperf
      8.  
        vxdmpadm allperf
      9.  
        vxdmpadm iostat
      10.  
        vxdmpadm cleardeviceperf
      11.  
        vxdmpadm cleararrayperf
      12.  
        vxdmpadm clearallperf
      13.  
        vxdmpadm setdsmscsi3
      14.  
        vxdmpadm setarrayscsi3
      15.  
        vxdmpadm setattr dsm
      16.  
        vxdmpadm setattr array
      17.  
        vxdmpadm setattr device
      18.  
        vxdmpadm setattr path
      19.  
        vxdmpadm set isislog
      20.  
        vxdmpadm rescan
      21.  
        vxdmpadm disk list
      22.  
        vxdmpadm getdsmattrib
      23.  
        vxdmpadm getmpioparam
      24.  
        vxdmpadm setmpioparam
  4. Performance tuning
    1.  
      Specifying control timer settings for an array
  5. Troubleshooting
    1. Resolving DMP issues
      1.  
        When a DMP license is no longer valid
      2.  
        When an unknown disk group appears in a DMP environment
    2. Using status information
      1.  
        Path status
      2.  
        Path states
  6. Glossary
    1.  
      Dynamic Multi-Pathing glossary

DMP overview

Dynamic Multi-Pathing (DMP) adds fault tolerance to disk storage by making use of multiple paths between a server or a host and a disk in a storage array. In previous releases, DMP was only available as a feature of Storage Foundation.

The paths on an array are set up to work in two ways - either in Active/Active mode, which provides load balancing of the data between multiple paths, or in Active/Passive mode, in which only one path is active and any remaining paths are backups.

The Dynamic Multi-Pathing functionality is offered as DMP device-specific modules (DSMs).

Note:

Windows Management Instrumentation (WMI) is a required service for the MPIO feature to work. Without this service, the MPIO Provider does not load and MPIO objects are not displayed on the VEA console or CLI command outputs. MPIO operations too cannot be performed in absence of WMI service.

DMP DSMs are designed to support a multi-path disk storage environment set up with the Microsoft Multipath I/O (Microsoft MPIO) solution. DMP DSMs work effectively with Windows to provide a fault tolerant multi-path disk storage environment. DMP DSMs have the following benefits:

  • Fiber Channel StorPort Miniport HBA Driver support

  • iSCSI HBA support

  • Microsoft iSCSI Software Initiator support

  • Boot from SAN support

  • Active/Active Dynamic Multi-Pathing with clustering support

  • DMP DSMs load balancing support

    Load balancing support includes the following:

    • Round robin load balancing support (Active/Active)

    • Fail Over Only (Active/Passive)

    • Dynamic Least Queue Depth load balancing support

    • Round robin with Subset load balancing support

    • Least Blocks load balancing support

    • Weighted Paths load balancing support

    • Balanced Path load balancing support

For DMP DSMs, Boot and data volumes are supported on the same bus/HBAs for non-clustered servers if the Boot from SAN recommendations from Microsoft is followed. DMP DSMs are not supported with Fibre Channel port drivers, Fibre Channel SCSI Miniport drivers or boot or cluster disks on the same bus/HBAs.