Date: Sat, 20 Mar 1999 10:00:04 +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: <19990320100004.J429@lemis.com> In-Reply-To: <36F2ABBF.9B789EDB@eboa.com>; from Roelof Osinga on Fri, Mar 19, 1999 at 08:55:43PM %2B0100 References: <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> <19990319150941.U429@lemis.com> <36F2ABBF.9B789EDB@eboa.com>
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On Friday, 19 March 1999 at 20:55:43 +0100, Roelof Osinga wrote: > Greg Lehey wrote: >> >> They're not superfluous. You're manipulating the structure of a block >> device, and you should use the character device for that. > > Could you run that by me again. If /dev/wd0s1g is the device holding > the structure I need to manipulate then what is the device I should > give as parameter to fsdb? /dev/rwd0s1g. >>> 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. > > It wasn't and still isn't. A TTY device is a character device and a > disk driver a block device. Well, in fact we have a block device interface and a character device interface, and they both talk to the same device. The difference is that the block interface is buffered and the character interface isn't. > And if it is the same then why give that error message/warning? Good point. It should refuse to do anything. When using fsdb, you want the changes to get back to disk immediately. You're not worried about performance. >>> This message sounds like a warning that you're about to do something >>> quite foolish. >> >> It is :-) > > Should then the man page not clarify such a folly? Probably. It did say to use a raw partition. >> Because it's a symlink: >> >> $ ls -l /etc/termcap >> lrwxrwxrwx 1 root wheel 23 Sep 28 1996 /etc/termcap -> /usr/share/misc/termcap > > Should've looked better. Still, is not fsdb intended for or primarily used > in single user mode. I.e. with most fs's unmounted? This is arguably a bug. /etc/termcap used to be a file, but they moved it to /usr/share/misc for some reason. I personally didn't agree, but it was a majority decision. To be fair, I can't see what fsdb even needs termcap for, but I suppose I could go look. Greg -- When replying to this message, please copy the original recipients. For more information, see http://www.lemis.com/questions.html See complete headers for address, home page and phone numbers finger grog@lemis.com for PGP public key To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
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