Patent ID: 8108364

Claim:
A method comprising, writing a first data unit with an associated first timestamp and a first epoch, wherein the first timestamp corresponds to time indicated by a system clock; subsequent to the writing of the first data unit, modifying the system clock by changing the time indicated by the system clock; subsequent to the modifying of the system clock, writing a second data unit with an associated second timestamp corresponding to the time indicated by the modified system clock, wherein no data units are written between the writing of the first data unit and the writing of the second data unit; in response to the writing of the second data unit, determining whether the first timestamp is behind the second timestamp in time; in response to determining that the first timestamp is behind the second timestamp in time, associating the second data unit with a second epoch; and in response to determining that the first timestamp is not behind the second timestamp in time, associating the second data unit with the first epoch.