Garbage Collection

Every umoci operation that modifies an image will not delete any now-unused blobs in the image (so as to ensure that any other operations that assume those blobs are present will not error out). However, this will result in a large number of useless blobs remaining in the image after operating on an image for a long enough period of time. umoci gc will garbage collect all blobs that are not reachable from any known image tag. Note that calling umoci gc between umoci unpack and umoci repack may result in errors if you’ve removed all references to the blobs used by umoci unpack.

% umoci gc --layout opensuse