1. A method comprising: during a low power state receiving a notification that a disk cache is inaccessible, and performing reads and writes from and to a hard disk without using the disk cache and logging information regarding writes to the hard disk performed while the disk cache is inaccessible; awaking from the low power state; accessing the log that includes information regarding previous the writes to the hard disk performed while the disk cache was inaccessible; determining if the log is corrupt or if the log has overflowed; in response to determining the log is corrupt or has overflowed, invalidating the entire disk cache; and in response to determining the log is not corrupt and has not overflowed, invalidating disk cache entries that correspond to the previous writes to the hard disk.