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Date: Wed, 10 Jan 1996 17:15:46 +1100
From: Bruce Evans <bde@zeta.org.au>
Message-Id: <199601100615.RAA29846@godzilla.zeta.org.au>
To: bde@zeta.org.au, msmith@atrad.adelaide.edu.au
Subject: Re: Add new slice to running system, comments?
Cc: hackers@FreeBSD.ORG, phk@critter.tfs.com
Sender: owner-hackers@FreeBSD.ORG
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>Hmm.  Now I'm a little confused 8)  Are you saying that the vn device maps
>the on-disk location of the file (its block map, I presume) and keeps
>this internally to avoid using the fs-specific read/write functions?  If
>this is the case, then I take everything back and will concentrate solely
>on using it 8)

The file system keeps the block map.  Read the code.  The vn driver could
keep an optimized form of the block map (one extent for contiguous files,
a few extents for slightly discontigous files...).  Write the code.

Bruce