[dune-pdelab] Very large .vtu files

[conf86 at web.de]

I'm currently trying to solve an instationary problem. 
If I take a coarse mesh the solution will be too imprecise, and if I take a finer mesh each .vtu file will be ~80 MB large. So when I have a lot of time steps (100 or more) this will take a lot of storage space on my limited home partition, especially as I need to solve the equation with different parameters.
Is there something simple that could be done in this case? Like doing the calculations with a fine mesh but creating a graphical output with lesser "resolution"? Or any other tips?

Thank you in advance!

Best regards