On occasion there is a need to tag SSD devices as such so that they are properly identified by your hosts and by vCenter. We can start by looking at our attached storage devices by running:
# esxcli storage core device list
This command outputs details about the storage devices connected to the host. For example:
As highlighted above, we are interested in the ‘Is SSD:’ line. Here we can see that this device has not been detected as SSD. We can get another opinion on this by seeing how the device/datastore is displayed in the vSphere client.
Again we can see that the device (in fact, all devices) are detected as Non-SSD. So how do we tag a device so that it is detected as SSD?
How to Tag SSD Devices
The process to tag a storage device as SSD involves creating a storage claim rule. First of all we need to identify the storage device we wish to tag, noting its device ID and the SATP associated with the device. We can start by listing the attached devices:
# esxcli storage nmp device list
This will output details about the connected devices and their associated SATP:
The next step is to add a PSA claim rule, marking the device as an SSD. We can do this by running the following:
esxcli storage nmp satp rule add -s SATP –device device_name –option=enable_ssd
Here we have specified that we want to use the same rule type but with the option added to enable SSD. Next we need to unclaim the device in order that we can claim it again using the new rule. To unclaim:
We can then reclaim the device using the following:
We can confirm it has worked by running the command we ran at the beginning of this to list the device properties:
esxcli storage core device list -d device_name
The device is now detected as SSD. We can confirm this in the vSphere client:
