Information Technology Reference
In-Depth Information
If the selected LUN has an existing VMFS partition, you will be presented with some dif-
ferent options; see the section “Expanding a VMFS Datastore” for more information.
10.
If you selected VMFS-3 in step 8, you'll need to select the VMFS allocation size.
For VMFS-5 datastores, you won't need to select a VMFS allocation size (VMFS-5 always
uses a 1 MB block size).
Refer back to “Examining the vSphere Virtual Machine File System” for more informa-
tion on block sizes and their impact.
11.
For both VMFS-5 and VMFS-3, in the Capacity section you'll specify how you want to
utilize the space on the selected LUN.
Generally speaking, you will select Maximize Available Space to use all the space avail-
able on the LUN. If, for whatever reason, you can't or don't want to use all of the space
available on the LUN, select Custom Space Setting and specify the size of the VMFS
datastore you are creating. Click Next when you are ready to proceed.
12.
At the Ready To Complete screen, double-check all the information. If everything is cor-
rect, click Finish; otherwise, use the Back button to go back and make any changes.
When you click Finish and i nish creating the datastore, vSphere will trigger the remain-
ing hosts in the same cluster to rescan for new devices. This ensures that the other hosts in the
cluster will also see the LUN and the VMFS datastore on that LUN. You will still need to rescan
for devices (using the process in the sections on adding a LUN) for ESXi hosts that are not in the
same cluster.
After you've created a VMFS datastore, you may need to complete a few extra tasks.
Although these tasks are storage-related, we've included them in other areas of the topic. Here's
a quick reference to some of the other tasks you might need to perform on a VMFS datastore:
◆
To enable Storage I/O Control, a mechanism for enforcing prioritized access to storage I/O
resources, refer to the section “Controlling Storage I/O Utilization” in Chapter 11.
To create a datastore cluster to enable Storage DRS, refer to “Introducing and Working with
Storage DRS” in Chapter 12, “Balancing Resource Utilization.”
◆
To create some alarms on this new VMFS datastore, refer to “Using Alarms” in Chapter 13,
“Monitoring VMware vSphere Performance.”
Creating new VMFS datastores is not the only way to make additional space available to
vSphere for use by VMs. Depending on your coni guration, you might be able to expand an
existing VMFS datastore, as we'll describe in the next section.
◆
Expanding a VMFS Datastore
Recall from our previous discussion of VMFS (in the section “Examining the vSphere Virtual
Machine File System”) that we mentioned that VMFS supports multiple extents. In previous
