Information Technology Reference
In-Depth Information
Storage I/O Control and Array Auto-Tiering
If your storage array supports auto-tiering—the ability for the array to seamlessly and transparently
migrate data between diff erent tiers (SSD, FC, SAS, SATA) of storage, be sure to double-check the
VMware Hardware Compatibility List (HCL) to verify that your array's auto-tiering functionality
has been certifi ed to be compatible with SIOC. A lso worth checking is your vendor documentation
for SIOC best practices. h e use of SIOC can undermine the auto-tiering that is built into some
storage arrays.
Assuming that your environment meets the requirements, then you can take advantage of
SIOC. Coni guring SIOC is a two-step process. First, enable SIOC on one or more datastores.
Second, assign shares or limits to storage I/O resources on individual VMs.
Let's look i rst at enabling SIOC for a particular datastore.
Enabling Storage I/O Control
SIOC is enabled on a per-datastore basis. By default, SIOC is disabled for a datastore, meaning
that you explicitly enable SIOC to take advantage of its functionality.
Datastores vs. Datastore Clusters
While SIOC is disabled by default for individual datastores, it is
enabled
by default for Storage DRS-
enabled datastore clusters that have I/O metrics enabled for Storage DRS. Refer to “Introducing and
Working with Storage DRS” in Chapter 12, “Balancing Resource Utilization,” for more information
on Storage DRS.
Perform the following steps to enable SIOC for a datastore:
1.
Launch the Web Client, if it is not already running, and connect to a vCenter Server
instance.
SIOC is available only when connected to vCenter Server, not when you are connected to
an individual ESXi host with the vSphere Client.
2.
Navigate to the Storage view.
3.
Select the datastore for which you want to enable SIOC.
➢
4.
Click the Manage
Settings tab.
5.
Select Edit (Figure 11.24).
6.
In the Datastore Capabilities dialog box, select Enabled under Storage I/O Control.
7.
Click OK.
SIOC is now enabled for the selected datastore; this is rel ected in the Datastore Capabilities
pane of the Web Client under the datastore manage tab, as you can see in Figure 11.25.
