vSphere Storage - ESXi 5.1 - Documentation - VMware

Requirements
To use the thin provision reporting feature, your host and storage array must meet the following requirements:
n ESXi version 5.0 or later.
n Storage array has appropriate firmware that supports T10-based Storage APIs - Array Integration (Thin
Provisioning). For information, contact your storage provider and check the HCL.
Space Usage Monitoring
The thin provision integration functionality helps you to monitor the space usage on thin-provisioned LUNs
and to avoid running out of space.
The following sample flow demonstrates how the ESXi host and the storage array interact to generate breach
of space and out-of-space warnings for a datastore with underlying thin-provisioned LUN. The same
mechanism applies when you use Storage vMotion to migrate virtual machines to the thin-provisioned LUN.
1 Using storage-specific tools, your storage administrator provisions a thin LUN and sets a soft threshold
limit that, when reached, triggers an alert. This step is vendor-specific.
2 Using the vSphere Client or the vSphere Web Client, you create a VMFS datastore on the thin-provisioned
LUN. The datastore spans the entire logical size that the LUN reports.
3 As the space used by the datastore increases and reaches the specified soft threshold, the following actions
take place:
a The storage array reports the breach to your host.
b Your host triggers a warning alarm for the datastore.
You can contact the storage administrator to request more physical space or use Storage vMotion to
evacuate your virtual machines before the LUN runs out of capacity.
4 If no space is left to allocate to the thin-provisioned LUN, the following actions take place:
a The storage array reports out-of-space condition to your host.
CAUTION In certain cases, when a LUN becomes full, it might go offline or get unmapped from the
host.
b The host pauses virtual machines and generates an out-of-space alarm.
You can resolve the permanent out-of-space condition by requesting more physical space from the
storage administrator.
Identify Thin-Provisioned Storage Devices
Use the esxcli command to verify whether a particular storage device is thin-provisioned.
In the procedure, --server=server_name specifies the target server. The specified target server prompts you
for a user name and password. Other connection options, such as a configuration file or session file, are
supported. For a list of connection options, see Getting Started with vSphere Command-Line Interfaces.
Prerequisites
Install vCLI or deploy the vSphere Management Assistant (vMA) virtual machine. See Getting Started with
vSphere Command-Line Interfaces. For troubleshooting , run esxcli commands in the ESXi Shell.
Procedure
Chapter 22 Storage Thin Provisioning
u Run the esxcli --server=server_name storage core device list -d=device_ID command.
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