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Subject: Re: tunefs
To: serges@umr.edu (Doug S.)
Date: Thu, 5 Oct 1995 16:30:51 -0700 (PDT)
Cc: freebsd-questions@freefall.freebsd.org
In-Reply-To: <m0t0vXK-0004I6C@nero.x10siv.org> from "Doug S." at Oct 5, 95 02:00:53 pm
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> Is there a way under FBSD to 'tunefs' the / filesystem, WITHOUT
> creating another filesystem and without making an existing filesystem
> bootable? 

(This is all to the best of my knowledge.  I may be wrong.  You've been
warned. :)

You must can only tunefs a dismounted filesystem - so you must do one of
a few things:

  * Boot off a "fixit" floppy that has a statically linked tunefs
    on it.

  * Boot off another partition.

Personally, I use the second method.  In a multi-disk system, I set up a
root filesystem on the second disk as well as the first.  I periodically
dump/restore the root filesystem to the "shadow" root.  The only
modification required on the shadow root is the location of root in
/etc/fstab.

This way I can still boot the system to perform maintenance even if my
root disk fails.  Makes reslicing your root disk easy instead of
requiring a reinstall.