A stub file looks and acts like a regular file. It has the same file attributes with the original physical file (file size, creation time, last write time, last access time). It also keeps the original file's security. The difference between the stub file and the normal physical file is the stub file doesn't take any physical space, looks like a 0 kb file.
here is the stub file snapshot:
A typical stub file has these attributes: offline attribute ( it tells the other applications the file data is not in local, e.g.,antivirus software, backup software they can skip these files); [url=http://www.easefilter.com/Forums_Files/Reparse%20Points.htm]reparse point[/url] attribute, you can put your data up to 14kb to the reparse point tab; [url=http://www.easefilter.com/Forums_Files/sparsefile.htm]sparse file attribute[/url].
When you or a Windows® application accesses a migrated file stub, the Windows operating system transparently directs a file access request to the HSM for Windows client file system filter driver. This driver retrieves the full file from the repository to which it was migrated.
When a file is restored but not changed, that file is "re-stubbed" during the next migration process.
When a file is recalled, modified, and migrated again, that new version of the file is stored in the Storage Manager storage.