Subject: Re: RFC: new mode bits in stat structure
To: None <tech-kern@NetBSD.ORG>
From: Ty Sarna <>
List: tech-kern
Date: 06/26/1998 18:06:58
In article <>,
Wolfgang Rupprecht  <> wrote:
>    2-level storage system.

No, it allows multiple levels.  The vfs layer just doesn't care about
anything other than wether the file is in the top layer or not.  The
actual details of moving files between layers is in a separate daemon. 
The VFS doesn't care where a file is when it's availible; it just needs
to know that it's not so it can ask the hsmd to bring it in.  If it's
there already, it just acts like nullfs.

>    storage can't both be presented as the same time.

I don't see the problem here. If you want a standard filesystem view of
the file, you use the standard API. If you want gory details, then there
should be an interface to the hsm daemon to query it about stuff like
what level a file resides at, etc.