Subject: Re: special-casing access to image files
To: None <>
From: der Mouse <mouse@Rodents.Montreal.QC.CA>
List: tech-userlevel
Date: 08/19/2001 20:35:21
>> I see this -F added to ~all filesystem utilities.  [...]

> Not to mention, don't you usually run things like fsck etc. on things
> that have been vnconfig'd?  Why not just run the fsirand there?

Usually, perhaps.  But it's nice to be able to fsirand a filesystem
image in a file that you own without needing to be root (which you have
to be to vnconfig).  Though I must admit that among my private patches
is one so that "options VND_NONPRIV" rips out the suser() in vndioctl,
allowing non-root to vnconfig.  (One thing that's really annoying about
vnd, and when I looked it looked hard to fix, is that you can't simply
use a read-only file and get a read-only `disk'.)

> WRT auto-detect:  I seem to recall having been able to run newfs/mkfs
> on a regular file in the past on other operating systems, with a
> warning printed at create time [...]

I looked at that too.  newfs uses the disklabel to get geometry info;
however, that's all it really needs the disklabel for.  Another of my
patches makes newfs willing to run on a filesystem image, or other
thing not supporting disklabels, provided you specify enough geometry
options (-s, -t, and -u).

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