Load Balanced Volume Groups

AHV hosts support load balancing of vDisks in a volume group for user VMs. Load balancing of vDisks in a volume group enables IO-intensive VMs to utilize resources such as the CPU and memory of multiple Controller VMs (CVMs). 

vDisks belonging to a volume group are distributed across the CVMs in a cluster thereby improving the performance and preventing bottlenecks. However, each vDisk still utilizes the resources of a single CVM.

Benefits:

• Provides exceptional throughput
• Allows Nutanix clusters to scale-up per application needs leveraging Nutanix’s scale-out architecture.

Use-Cases:

• Large databases or high-performance applications that require lots of IO per VM

Note:

• vDisk load balancing is disabled by default.
• You can attach a maximum number of 10 load-balanced volume groups per user VM.
• For Linux VMs, ensure that the SCSI device timeout is 60 seconds. For more information about checking and modifying the SCSI device timeout, see the Red Hat documentation here.

1. Log on to a Controller VM with SSH.
2. Access the Acropolis command line.nutanix@cvm$ acli
   <acropolis>
3. Do one of the following:
   1. Enable vDisk load balancing if you are creating a new volume group.<acropolis> vg.create vg_name load_balance_vm_attachments=true
      Replace vg_name with the name of the volume group.
   2. Enable vDisk load balancing if you are updating an existing volume group.
      <acropolis> vg.update vg_name load_balance_vm_attachments=trueReplace vg_name with the name of the volume group.
4. Optional: Disable vDisk load balancing.<acropolis> vg.update vg_name load_balance_vm_attachments=falseReplace vg_name with the name of the volume group.

Thanks for Reading!