Windows 10 and reserved storage
Microsoft informs on its blog about new feature in upcoming Windows 10 April Update to keep Windows 10 up to date
How does it work?
When apps and system processes create temporary files, these files will automatically be placed into reserved storage. These temporary files won’t consume free user space when they are created and will be less likely to do so as temporary files increase in number, provided that the reserve isn’t full. Since disk space has been set aside for this purpose, your device will function more reliably. Storage sense will automatically remove unneeded temporary files, but if for some reason your reserve area fills up Windows will continue to operate as expected while temporarily consuming some disk space outside of the reserve if it is temporarily full.
How much of my storage is reserved?
In the next major release of Windows (19H1), we anticipate that reserved storage will start at about 7GB, however the amount of reserved space will vary over time based on how you use your device. For example, temporary files that consume general free space today on your device may consume space from reserved storage in the future. Additionally, over the last several releases we’ve reduced the size of Windows for most customers. We may adjust the size of reserved storage in the future based on diagnostic data or feedback. The reserved storage cannot be removed from the OS, but you can reduce the amount of space reserved.
Testing out reserved storage
This feature is available to Windows Insiders running Build 18298 or newer.
Source : Microsoft