Patent ID: 7496609

Claim:
A method for maintaining correct metadata regarding a file system, said method comprising: monitoring traffic to said file system; collecting metadata regarding said file system using said monitored traffic; tracking reliability information regarding which of said collected metadata may be inaccurate in case of an abnormal shutdown of said file system; and upon restarting, replacing a portion of said metadata by requesting information from said file system, said portion determined using said reliability information, where said portion is not equal to all of said metadata, wherein said step of tracking reliability information comprises: identifying when said monitored traffic comprises a first command to said file system which will cause a specific portion of said metadata to be unreliable when said file system undergoes an abnormal shutdown; storing a flag value associated with said specific portion, said flag value indicating, when said determination is that said monitored traffic includes a command to said file system which will cause said specific portion of said metadata to be unreliable, that said portion should be replaced upon restarting; and identifying when a prescribed period of time has elapsed in which no command to said file system has been issued which will cause said specific portion of said metadata to be unreliable, then changing said flag value to indicate that said specific portion need not be replaced upon restarting.