Patent ID: 7680998
Filing Date: 2010-03-16
Classification: G06F

Abstract:
1. A method of generating a backup file on a client, the method comprising: determining by a client that a hash file system server is not currently able to contemporaneously process a backup from the client, the client including a computer device, wherein the backup is a backup of a file directory accessible to the client; breaking each file of the file directory into one or more pieces; writing by the client a root tag vector to a journal file accessible to the client, wherein the root tag vector includes one or more root hashes stored in one or more caches accessible to the client and wherein the one or more caches additionally store one or more entries representing data protected by the one or more root hashes, wherein each of the one or more entries includes a tag field that is n bits long and a hash of a piece of data, wherein the n bits in the tag field correspond to the one or more root hashes stored in the one or more caches of the client, and each tag bit indicates whether a corresponding root hash protects the entry; determining by the client that the one or more pieces of data of the backup are not identical to data represented by the one or more entries by performing a hash on each of the one or more pieces of data and comparing each hash to the one or more entries; and recording by the client, in the journal file on a storage device, one or more requests to store the one or more pieces of data, wherein the one or more requests to store the one or more pieces of data can be processed by the hash file system server at a later time when the hash file system server is able to process the backup.