6.0

Procedure
1 Select the datastore in the vSphere Client inventory and click the Performance tab.
2 From the View drop-down menu, select Performance.
For more information, see the vSphere Monitoring and Performance documentation.
Set Storage I/O Control Resource Shares and Limits
Allocate storage I/O resources to virtual machines based on importance by assigning a relative amount of
shares to the virtual machine.
Unless virtual machine workloads are very similar, shares do not necessarily dictate allocation in terms of
I/O operations or megabytes per second. Higher shares allow a virtual machine to keep more concurrent I/O
operations pending at the storage device or datastore compared to a virtual machine with lower shares. Two
virtual machines might experience different throughput based on their workloads.
Prerequisites
Launch the vSphere Client and log in to a vCenter Server system.
Procedure
1 Select a virtual machine in the vSphere Client inventory.
2 Click the Summary tab and click Edit Settings.
3 Click the Resources tab and select Disk.
4 Select a virtual hard disk from the list.
5 Click the Shares column to select the relative amount of shares to allocate to the virtual machine (Low,
Normal, or High).
You can select Custom to enter a user-defined shares value.
6 Click the Limit - IOPS column and enter the upper limit of storage resources to allocate to the virtual
machine.
IOPS are the number of I/O operations per second. By default, IOPS are unlimited. You select Low
(500), Normal (1000), or High (2000), or you can select Custom to enter a user-defined number of shares.
7 Click OK.
Shares and limits are reflected on the Resource Allocation tab for the host and cluster.
Enable Storage I/O Control
When you enable Storage I/O Control, ESXi monitors datastore latency and adjusts the I/O load sent to it, if
datastore average latency exceeds the threshold.
Prerequisites
Launch the vSphere Client and log in to a vCenter Server system.
Procedure
1 In the vSphere Client inventory, select a datastore and click the Configuration tab.
2 Click Properties.
3 Under Storage I/O Control, select the Enabled check box.
4 Click Close.
Chapter 25 Resource Management for Single Hosts
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