Patent ID: 7111136

Claim:
A method for processing data in an application data store comprising: producing at least a first snapshot of an application data store, the application data store configured to receive data by way of write operations issued from a host device; storing each journal entry for each write operation issued from the host device in a journal data store, thereby accumulating a list of journal entries; monitoring an amount of free space on the journal data store; when the amount of free space falls below a first threshold value, then removing one or more journal entries from the journal data store, thereby increasing the amount of free space, wherein enough of the journal entries are removed so that the amount of free space rises above a second threshold value, and wherein each journal entry comprises a fixed-size header portion and a variable-size data portion, wherein the journal data store comprises a first storage area within which a plurality of header portions are defined and a second storage area for storing a plurality of data portions, and wherein storing a journal entry includes allocating one of the journal headers and allocating a sufficient amount of space in the data portion to contain data associated with the write operation.