shelved files and SAMBA

John Malmberg wb8tyw at
Fri Mar 22 16:30:03 GMT 2002

Christopher R. Hertel wrote:
> Just a question... Would it be possible to cache the icons only?

Not really.

> Assuming that you would be implementing shelved file support using a VFS 
> layer, would it be possible to detect--within the VFS layer--when the 
> access was for the icons only?  Perhaps by watching for byte-ranges or 
> particular calls that look for icons?

The problem is that the shelved file system is implemented by a third 
party add on.  So you have no control or knowledge about what is left on 
the stub file on the disk.

Also I do not know if there is any standard place in a file that 
Microsoft Windows Explorer knows to find an ICON.  It could vary with 
the type of file.  And also there is the settings where Explorer 
displays miniature thumbnails of graphics.

This is why you need to find out if the client can deal with the shelved 
attribute before letting it know that the file exists and has a shelved 

> If you could do this, then the VFS layer would need only have the icon 
> itself on the fast storage.  The reset would be retrieved from slow 
> storage only if accessed.

So the VFS layer that is presenting the file to SAMBA can not cache the
icon with out threshing the whole directory.  And it would have to cache
the icons somewhere.  Remember when dealing with a shelving file system,
you are potentially dealing with thousands, possibly millions of files.

> Not sure how practical that is....

Start looking at the scale of what a shelved file system is used for, 
and it becomes apparent to me that it is not practical.

Now who actually has a shelving file system to test a Microsoft client 

wb8tyw at

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