A key aspect of any file system is how to recover if a system crash occurs. Earlier methods required a time-consuming scan of the entire file system. A better solution is the method of logging (or journaling) the metadata of files.

VxFS logs new attribute information into a reserved area of the file system, whenever file system changes occur. The file system writes the actual data to disk only after the write of the metadata to the log is complete. If and when a system crash occurs, the system recovery code analyzes the metadata log and tries to clean up only those files. Without logging, a file system check (fsck) must look at all of the metadata.

Intent logging minimizes system downtime after abnormal shutdowns by logging file system transactions. When the system is halted unexpectedly, this log can be replayed and outstanding transactions can be completed. The recovery time for file systems can be reduced to a few seconds, regardless of the file system size.

By default, VxFS file systems log file transactions before they are committed to disk, reducing time spent recovering file systems after the system is halted unexpectedly.