VCP6-DCV Delta Study – Section 3 – Objective 3.5

This post covers Section 3, Configure and Administer Advanced vSphere Storage, Objective 3.5, Setup and Configure Storage I/O Control.

The vSphere Knowledge covered in this objective:

  • Enable/Disable Storage I/O Control
  • Configure/Manage Storage I/O Control
  • Monitor Storage I/O Control

Objective 3.5 VMware Resources:

– Enable/Disable Storage I/O Control
Enable Storage I/O Control in the vSphere Resource Management Guide on page 49.
Storage I/O Control (SIOC) extends the constructs of shares and limits to handle storage I/O resources.

Steps to enable SIOC:

  • Enable Storage I/O Control for the datastore.
  • Set the number of storage I/O shares and upper limit of I/O operations per second (IOPS) allowed for
    each virtual machine.

By default all virtual machines are set to Normal (1000) shares with unlimited IOPS.

Enabling SIOC on a datastore:

– Configure/Manage Storage I/O Control
Managing Storage I/O Resources in the vSphere Resource Management Guide on page 47.

SIOC Requirements and Limitations:

  • Datastores that are Storage I/O Control-enabled must be managed by a single vCenter Server system.
  • SIOC is supported on Fibre Channel-connected, iSCSI-connected, and NFS-connected storage. Raw Device Mapping (RDM) is not supported.
  • SIOC is not supported for datastores with multiple extents.
  • Before using SIOC on datastores that are backed by arrays with automated storage tiering capabilities, check the VMware Storage/SAN Compatibility Guide to verify whether the automated tiered storage array has been certified to be compatible with SIOC.

SIOC will not function correctly if you share the same spindles on two different datastores.

Configure SIOC for a datastore:
The congestion threshold value for a datastore is the upper limit of latency that is allowed for a datastore before SIOC assign importance to the virtual machine workloads based on their allocated shares.

Setting SIOC Shares and IOPS Limit on a Virtual Machine Disk
Allocate storage I/O resources to virtual machines based on importance by assigning a relative amount of shares to the virtual machine.

– Monitor Storage I/O Control
Monitor Storage I/O Control Shares in the vSphere Resource Management Guide on page 48.

Use the datastore Performance tab to monitor how SIOC is handling IO of virtual machines access the datastore based on the virtual machine shares.

Performance charts allow the following information to be monitored:

  • Average latency and aggregated IOPS
  • Hosts’ Latency
  • Hosts’ Queue Depth
  • Hosts’ Read and Write IOPS
  • Virtual Machines’ Disks Read and Write Latency
  • Virtual Machines’ Disks Read and Write IOPS


More Section Objectives in the VCP6-DCV Delta Exam Study Guide Index

I hope you found this helpful. Feel free to add anything associated with this section using the comments below. Happy studying.

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