I posted shortly after ESXi 6.0 came out a while back explaining how to do in-guest UNMAP with Windows. See the original post here:
Direct Guest OS UNMAP in vSphere 6.0
The high-level workflow if you don’t want to read the post is:
- You delete a file in Windows
- Run Disk Optimizer to reclaim the space
- Windows issues UNMAP to the filesystem
- ESXi shrinks the virtual disk
- If EnableBlockDelete is enabled on the ESXi hosts, ESXi will issue UNMAP to reclaim the space on the array
This had a few requirements:
- ESXi 6.0+
- VM hardware version 11+
- Thin virtual disk
- CBT cannot be enabled (though this restriction is removed in ESXi 6.5 see this post)
Continue reading “Allocation Unit Size and Automatic Windows In-Guest UNMAP on VMware”