Over the past few days, Timed Media Handler has consistently refused to transcode a substantial number of videos (I'm estimating around a hundred or so) at certain resolutions, even when reset. The original files are still 'visible' (it's not that bug), and the failures only apply to specific resolutions (that are persistent for the particular file, but not across different files). When reset, the transcode runs for a substantial period of time (around what would be expected), and then fails.
The error message in Quarry is "* An unknown error occurred in storage backend "local-swift-eqiad". * An unknown error occurred in storage backend "local-swift-codfw"."