Light Cache data is saved in the resumable files, but the Irradiance Map (or any other GI map) is not and needs to be recalculated when resuming. The rendering should still continue from where it was stopped after the GI data is recalculated.
Enable the Resumable Rendering option before starting a new render, not only when resuming.
To start a new render, delete the .vrimg/.vrprog file.
Do not change the scene between stopping and resuming, except for the Progressive sampling options (Min. subdivs, Max. subdivs, Render time, Noise threshold).
Resumable Rendering does not support tiled EXR outputs.
If rendering with V-Ray Standalone, use the -deleteResumableFileOnSuccess=1 command to automatically delete the resumable file if the frame is completed successfully. This applies to additional .vrimg or .vrprog files, and not when the output image file is .vrimg. The default command value is 0, which keeps the resumable file.
Currently, the Delete resumable data for completed frames option is not supported on V-Ray GPU.
