Patent ID: 7912815

Claim:
A method comprising: remotely communicating with a storage server that maintains a write-out-of-place file system, the file system including an active file system and a persistent point-in-time image (PPI) of the active file system, wherein the PPI includes a reference to at least part of the active file system when the PPI is created, but does not duplicate said part of the active file system; and automatically monitoring utilization of storage space of the file system, including: automatically determining a data overwriting rate of the file system; automatically monitoring free space available to the file system; and calculating a probability of a write failure to the file system occurring within a specified unit of time, based on the data overwriting rate and the free space available to the file system, wherein the probability of a write failure to the file system occurring within the specified unit of time is defined as x/y, wherein x is the data overwriting rate of the file system and y is an amount of free space of the file system.