Date: Fri, 19 Mar 1999 15:09:41 +1030 From: Greg Lehey <grog@lemis.com> To: Roelof Osinga <roelof@eboa.com> Cc: freebsd-questions@FreeBSD.ORG Subject: Re: Have crashed, won't travel Message-ID: <19990319150941.U429@lemis.com> In-Reply-To: <36F1BDBB.E9E4F323@eboa.com>; from Roelof Osinga on Fri, Mar 19, 1999 at 04:00:11AM %2B0100 References: <19990304095813.I441@lemis.com> <36DDEFFD.A4DB4978@eboa.com> <19990304130126.B441@lemis.com> <36DE0352.E99BCB70@eboa.com> <19990316174710.H429@lemis.com> <36EE54A4.8DC53017@eboa.com> <19990317093436.G429@lemis.com> <36EFC56A.ACBFB0A7@eboa.com> <19990318100818.L429@lemis.com> <36F1BDBB.E9E4F323@eboa.com>
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On Friday, 19 March 1999 at 4:00:11 +0100, Roelof Osinga wrote:
> Greg Lehey wrote:
>>
>>> Hm. Same of course with 'rm -f PLIST'. Can't even rename it. Something's
>>> fishy in the state of Denmark (to quote Inspector Clouseau).
>>
>> Looks like it's time to learn to use fsdb. I've never used it myself,
>> but from the man page you should be able to go in there and remove the
>> entries.
>
> Pretty much a straightforward operation. You cd to the directory and
> rm the file by name.
I thought that caused a panic.
> Constructive (intended :) criticisms:
>
> One thing is that when fsdb comes up it does so with the message:
>
> /dev/wd0s1g is not a character device
> CONTINUE? [yn]
>
> I mean, I thought that was the whole point of the excercise. To
> manipulate a block device's inode tables. So why ask confusing
> questions when they are clearly superfluous.
They're not superfluous. You're manipulating the structure of a block
device, and you should use the character device for that.
> The man page doesn't mention it.
I read:
Fsdb opens fsname (usually a raw disk partition) and runs a
command loop allowing manipulation of the file system's inode
data.
In case it's not clear, a raw partition and a character device mean
this same thing in this context.
In one point, though, you're correct. From System V we see:
The fsdb command reads a block at a time and will therefore work
with raw as well as block I/O.
BSD is different in this area. We also have some bogons hiding in the
shadows. I've seen non-reproducible panics when running newfs on a
block device, for example.
> This message sounds like a warning that you're about to do something
> quite foolish.
It is :-)
> Usually one presents such messages to warn folk that the device
> given is not of the type normally used. To wit, a character device.
Correct.
> Also it ends with:
>
> No entry for terminal type "cons25"
> using dumb terminal settings
>
> Which of course leads one to believe it comes complete with
> a fancy visual editor.
It's certainly interesting to know what it uses it for.
> Also, I think most uses will be in single user mode with nada but
> the root mounted. So why bother searching for a terminal type at
> all? Hm. Come to think of it. termcap is in /etc and was part of the
> root device. So why didn't it find cons25?
Because it's a symlink:
$ ls -l /etc/termcap
lrwxrwxrwx 1 root wheel 23 Sep 28 1996 /etc/termcap -> /usr/share/misc/termcap
I suppose you could argue that; if you want to, send-pr is your
friend.
Greg
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