Of course, the timing depends on the usage pattern. In our case we write a lot to the disks, which means they fail faster. Time to failure also depends on manuf

Of course, the timing depends on the usage pattern. In our case we write a lot to the disks, which means they fail faster. Time to failure also depends on manufacturer, batch, server conditions... But in general I wouldn't trust too much that have been continuously running under a significant load (I don't think a Netflix cache server had a lot of idle time) for so many years.