How to remove files created by 'mknod'? (kernel version 2...

Hi all,
I cannot delete files created by 'mknod'. I used a subdir in my home
directory (NFS mounted) as a staging area for Linux filesystem contents
that were used as inputs to mkfs.* utilities.
Now I am done and want to get rid of all the files, for example, in
...../dev.

MYHOST ~/staging-area % ls -l dev
total 4
crw------- 1 root root 5, 1 Jun 2 21:18 console
crw-rw---- 1 root root 5, 64 Jun 2 21:18 cua0
crw-rw---- 1 root root 5, 65 Jun 2 21:18 cua1
brw-rw---- 1 root root 3, 0 Jun 2 21:18 hda
brw-rw---- 1 root root 3, 1 Jun 2 21:18 hda1
......
crw------- 1 root root 4, 66 Jun 2 21:18 ttyS2
crw------- 1 root root 4, 67 Jun 2 21:18 ttyS3
crw-r--r-- 1 root root 1, 9 Jun 2 21:18 urandom
crw-rw-rw- 1 root root 1, 5 Jun 2 21:18 zero

MYHOST ~/staging-area % sudo rm -ri dev
rm: descend into directory `dev'? y
rm: remove character special file `dev/mem'? y
rm: cannot remove `dev/mem': No such file or directory
rm: remove character special file `dev/kmem'? y
rm: cannot remove `dev/kmem': No such file or directory
rm: remove character special file `dev/null'? y
rm: cannot remove `dev/null': No such file or directory
rm: remove character special file `dev/zero'? y
rm: cannot remove `dev/zero': No such file or directory

MYHOST ~/staging-area % sudo unlink dev/zero
unlink: cannot unlink `dev/zero': No such file or directory

MYHOST ~/staging-area % sudo debugfs .
debugfs 1.32 (09-Nov-2002)
..: Attempt to read block from filesystem resulted in short read while
opening filesystem
debugfs: open dev
dev: Attempt to read block from filesystem resulted in short read while
opening filesystem
debugfs: open .
..: Attempt to read block from filesystem resulted in short read while
opening filesystem
debugfs: rm dev/zero
rm: Filesystem not open

So, how do you remove files created by 'mknod'?

On 23 Jun 2005 11:14:47 -0700, knighttof3 RemoveThis @yahoo.com staggered into the
Black Sun and said:
> I cannot delete files created by 'mknod'. I used a subdir in my home
> directory (NFS mounted) as a staging area for Linux filesystem
> contents that were used as inputs to mkfs.* utilities.

NFS and device nodes are... interesting. You can create one, sure, but
trying to open() or read() or write() to it may not have the effect you
desire. The general rule is probably something like "don't bother to
have device nodes on NFS" except for weird cases like root-on-NFS.

> MYHOST ~/staging-area % ls -l dev
> crw------- 1 root root 5, 1 Jun 2 21:18 console
> crw-rw---- 1 root root 5, 64 Jun 2 21:18 cua0
[snip]
> MYHOST ~/staging-area % sudo rm -ri dev
> rm: remove character special file `dev/mem'? y
> rm: cannot remove `dev/mem': No such file or directory

....ah. How annoying. ssh in to the machine where the files live and
kill them there; that has a much higher probability of success.

> MYHOST ~/staging-area % sudo debugfs .
> debugfs 1.32 (09-Nov-2002)
> .: Attempt to read block from filesystem resulted in short read while
> opening filesystem
> debugfs: open dev
> dev: Attempt to read block from filesystem resulted in short read while
> opening filesystem

....? debugfs doesn't do NFS. If "dev" is loopback mounted (mount -o
loop /path/to/some/file /mnt/somewhere), no need to fiddle around with
all this, just umount the filesystem and rm /path/to/some/file if you're
done with it. Also, if dev is loopback mounted, debugfs will work
better if you umount the filesystem and run debugfs on the file.

> So, how do you remove files created by 'mknod'?

With rm. Works fine IME. I think NFS and possibly a loopback mount are
throwing monkey wrenches into the whole thing here, though. HTH anyway,

--
Matt G|There is no Darkness in Eternity/But only Light too dim for us to see
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