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Configure MPIO
22 Dell EMC SC Series Storage and Microsoft Multipath I/O | CML1004
3. Once the server reboots, use Disk Management to verify that the configuration is correct. There
should only be one instance of each SAN volume listed in Disk Management.
5.2 Changing the default load balance policy
Once SC Series volumes are associated with the Microsoft DSM on a Windows server, no further steps are
necessary unless changing the Windows default MPIO load balance policy is necessary. The default load
balance policy on a Windows server can be changed system-wide or on a per-volume basis.
The supported Windows Server MPIO policies are as follows:
• Dell Storage Center OS (SCOS) 6.5 and earlier: round robin (default) and failover only
• SCOS 6.6 and later: round robin (default), failover only, and least queue depth
Live Volume Asymmetric Logical Unit Access (ALUA), with SCOS 7.3 and newer, supports round
robin with subset, and failover only. Windows Server 2016 with the March 2018 cumulative update
and newer offers full support for Live Volume ALUA. Windows Server versions prior to 2016 with the
March 2018 cumulative update offer limited support for Live Volume ALUA. For more information, see
the document, Dell EMC SC Series Storage: Synchronous Replication and Live Volume.
• SAS FE: round robin with subset (default), least queue depth, and weighted paths
To change the system-wide Windows default MPIO load balance policy to another supported load balance
policy, use MPCLAIM or PowerShell.
5.2.1 Using the MPCLAIM command
To use the MPCLAIM command to change the default load balance policy, open a command prompt with
elevated (administrator) privileges and enter the following:
mpclaim.exe -L -M <0-7> -d "COMPELNTCompellent Vol"
<0-7> refers to the desired load balance policy as shown in Table 1.
MPCLAIM load balance options
Parameter
Definition
0
Clear the policy
1
Failover only
2
Round robin
3
Round robin with subset
4
Least queue depth
5
Weighted paths
6
Least blocks
7
Vendor specific
For example, to change all SC Series volumes to a failover only policy, enter the following command:
mpclaim.exe -L -M 1 -d "COMPELNTCompellent Vol"