Patent ID: 7320059
Filing Date: 2008-01-15
Classification: G06F

Abstract:
1. In a computer system comprising a first storage system comprising at least one first storage device, a second storage system comprising at least one second storage device, and at least one communication link that couples the first storage system and the second storage system, wherein the at least one second storage device is slower than the at least one first storage device, wherein the second storage system stores content units in a file system on the second storage system, the file system having a plurality of directories arranged in a tree, comprising at least one root directory and a plurality of non-root directories that each has a parent directory, wherein at least one of the plurality of directories in the tree corresponds to a period of time subsumed by a period of time corresponding to its respective parent directory, a method comprising acts of: (A) scheduling, at the second storage system, a time of deletion for a content unit from the first storage system by storing, in at least one of the plurality of directories that corresponds to a period of time that includes the scheduled time of deletion, an indication to delete the content unit from the first storage system; (B) receiving, at the second storage system, a first request to store a copy of the content unit stored on the first storage system; (C) in response to the first request, storing the copy of the content unit on the second storage system; and (D) sending a second request from the second storage system to the first storage system to delete the content unit stored on the first storage system.