Add the instruction:
to the file
to remove all "write reserve" for a given manager. This value is read only at startup, so you must restart the manager for the change to take effect.
The default algorithm for ViaB is 10-15% of the image. The manager will assume that each desktop will use at least that much space and refuse to provision additional desktops if sufficient free space on the desktop drive is no longer available.
There are certain use cases where the default reserve is overly conservative; this gives the ViaB administrator additional control over the environment in those situations.