Editing MAC times (section)

== Metadata issues ==

As with all file system metadata, user expectations about MAC times can be violated by programs which are not metadata-aware. Some file-copying utilities will explicitly set MAC times of the new copy to match those of the original file, while programs that simply create a new file, read the contents of the original, and write that data into the new copy, will produce new files whose times do not match those of the original.

Some programs, in an attempt to avoid losing data if a write operation is interrupted, avoid modifying existing files. Instead, the updated data is written to a new file, and the new file is moved to overwrite the original. This practice loses the original file metadata unless the program explicitly copies the metadata from the original file. Windows is not affected by this due to a workaround feature called '''File System Tunneling'''.<ref>
  {{cite web
    | url = https://support.microsoft.com/en-us/kb/172190
    | title = Windows NT Contains File System Tunneling Capabilities
    | publisher = Microsoft Support
  }}
</ref>