https://www.datacenterknowledge.com/data-center-faqs/facebook-data-center-faq
.
https://www.google.com/search?client=ms-android-h3g-gb&ei=43cfXKnSJOeI1fAPjImtmAU&q=youtube+storage+facility&oq=youtube+storage+facility&gs_l=mobile-gws-wiz-serp.3..0.6720.12766..13782…1.0..1.324.4444.0j6j10j3……0….1………0i71j35i304i39j0i7i30j0i13j0i67.KTda-p_WFS8
.
https://www.quora.com/What-is-the-total-size-storage-capacity-of-YouTube-and-at-what-rate-is-it-increasing-How-is-Google-keeping-up-with-the-increasing-demands-of-Youtube’s-capacity-given-that-thousands-of-videos-are-uploaded-every-day