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

vxdmpadm setattr dsm

vxdmpadm setattr dsm [loadbalancepolicy=FO|RR|LQ|LB|BP [blockshift=#]] [primarypath=#] [testpathretrycount=# scsicmdtimeout=# kernalsleeptime=# failoverretrycount=#] <DiskName> | p#c#t#l#> [dsmName=ALL | <DsmFileName>]

This command sets the load balance policy and primary path of the DSM to which the designated disk belongs. It also lets you set tunable parameters (control timer settings) that affect the testing and failover of the paths. The following attributes apply:

loadbalancepolicy=

FO|RR|LQ|

LB|BP

Specifies the load balance policy for the DSM where:

  • FO specifies Fail Over Only (Active/Passive)

  • RR specifies Round Robin (Active/Active)

  • LQ specifies Dynamic Least Queue Depth

  • LB specifies Least Blocks

  • BP specifies Balanced Path

blockshift=#

# specifies the number of contiguous I/O blocks that are sent along a path to an Active/Active array before switching to the next available path.

(Default value is 2048 blocks.)

primarypath=#

# specifies the primary path of the DSM. For example, primarypath=1-1-1 sets path 1-1-1 as the primary path of the DSM.

testpathretrycount=#

Range: 0 ~ 50 times. Default: 0.

scsicmdtimeout=#

# specifies the amount of time a SCSI command waits for a device to respond to a SCSI command. Default is 30 seconds. Maximum is 120 seconds.

kernalsleeptime=#

# specifies the interval of time the DMP DSMs kernel waits between attempts to recover a path from an error condition. Default is 200 milliseconds. Maximum is 10000 milliseconds.

failoverretrycount=#

# specifies the number of times DMP DSMs attempts a failover to another path when the current path fails. Default is 0. Maximum is 50 times.

Note:

For DMP DSMs, Failover Retry Count does not apply to the EMC Symmetrix array.

<DiskName>

The designated disk, which can be specified by the device name (such as Harddisk2).

p#c#t#l#

The #s correspond to the port, channel, target, and LUN of a disk.

dsmName = ALL |<DsmFileName>

Specifies whether to apply settings to all installed DSMs or only to the DSM specified by file name. Only the load balance policy settings are applied. If other settings are specified, the command returns an error.

Note:

This parameter can be applied with or without a storage connection. If the array hasn't been configured with load balance settings previously, it inherits the load balance settings that are specified for the DSM once it is connected. However, if the array was previously connected and has been configured with load balance settings in the registry, the previous settings are maintained when the array is reconnected.

Example

vxdmpadm setattr dsm loadbalancepolicy=FO 
primarypath=1-1-0 scsicmdtimout=34 Harddisk6

Sets the load balance policy of the DSM to Fail Over Only (Active/Passive), the primary path to path 1-1-0, the scsicmdtimeout to 34 seconds.