+size of the compressed output per volume. Multiple values may be given
+as a single argument separated by commas. Each value will be used for one
+dump volume in the order listed; if
+.B dump
+creates more volumes than the
+number of values given, the last value will be used for the remaining
+volumes. This is useful for filling up already partially filled media
+(and then continuing with full size volumes on empty media) or mixing media
+of different sizes.