I had a big rectangular sun shade sail over a big rooftop deck years ago and it was awesome. The deck had 4' walls and 8' posts so I just hung it from those, with a post extension at one corner to give it a peak. I mounted one side with ratcheting straps (the kind you use to tie stuff tightly to your car roof etc.) so I could pretty quickly furl & unfurl it - it tucked rolled up along the tops of the deck posts along one side when furled. And I'd have some of them now if not for some huge trees shading my entire patio.