***********UPDATE PLEASE REFER TO THE POST AT THIS LINK FOR UPDATED INFORMATION ON THIS SCRIPT***********************

The most common request I get for scripts here at Pure Storage is an UNMAP script using PowerCLI. I have a basic one here that does the trick–UNMAPs Pure Storage volumes in a vCenter. That being said it is pretty dumb–doesn’t tell you much about what happened other than what volumes it is reclaiming (or not reclaiming) and moves on. A few requests have come in recently for something a little more in-depth. Most notably the ability to see how much space has been reclaimed. This information cannot be gathered from the VMware side of things–it has to come from the FlashArray.

There are two options here–either use our REST APIs or use our PowerShell toolkit to get this information (which just wraps the REST calls). For this script I chose to use the REST API directly from within PowerShell. What this script does is:

1. Connects to the vCenter and FlashArray
2. Finds all of the datastores and counts how many are actually Pure Storage volumes (NAA comparison)
3. Iterates through all of the datastores
4. Skips it if it is not Pure
5. If it is, the current data reduction ratio is reported and so the is current physical written capacity on the FlashArray.
6. Runs UNMAP on the datastore
7. Reports the new data reduction and physical space after UNMAP completes and how much was reclaimed.
8. Repeats for the rest of the volumes.

The script reports all of this to the console window, but it always throws it in a log file through add-content. If you don’t want it to return the info to the console, simply delete the write-host lines. If you don’t want it to log, delete the add-content lines.

There are a few required parameters–vCenter information (IP, username, password), FlashArray info (IP, username, password), UNMAP block count and a log file location. These are hard-coded parameters, but that can easily be changed by altering it to a read-host.

You may also note that after each UNMAP the script sleeps for 60 seconds–I do this so I make sure the FlashArray has time to update its information right after the UNMAP. 60 seconds is VERY conservative–probably 10 or so is fine, so feel free to mess with that number if you don’t like waiting. I also have another sleep at the end of each datastore operation to give a quick chance to review the latest results before it starts spewing the next datastore information on the screen (note this update didn’t make it into the video demo below–it doesn’t wait after each datastore).

See the script in action below. Essentially I am deleting a bunch of VMs across 4 datastores and then running the UNMAP. You can see the space get reclaimed on the FlashArray.

Note: You need particular access (see a blog post about that here) to vCenter to run UNMAP. For the FlashArray only Read Only is needed (higher of course is fine too).

Get the script here:

https://github.com/codyhosterman/powercli/blob/master/unmapsdk.ps1