Baslinux mailing list

[James Miller <jamtat AT mailsnare.net>]

On Fri, Jan 12, 2007 at 02:45:25PM +0000, sindi keesan wrote:
> 
> I presume this is to unload lilo from the master boot record (which is not 
> a partition so you cannot repartition to remove it).  Does not BL3.40 
> 2-floppy set have lilo on it already, which you could run with a switch to 
> remove it (lilo -u or /u ?).

Would this work if BL had not installed lilo to the drive? I think maybe this 
process would 
rely on some config file lilo created when it was installed. That said, I'm 
not sure I ever 
tried to unistall lilo . . .

I believe some newbie-oriented interpretation is in line for  the following:

> You should not need to install Caldera Linux in order to read the help 
> files on it, just mount the CD (mount /dev/hdc /mnt if secondary master, 
> or dmesg|less to see if it is hdc first, it could be hdb or hdd) and read 
> from it.

To look at the contents of diskette's, CD's--as well as other drives and/or 
partitions that 
were not hooked to your system and detected when you initially installed 
Linux--you need to 
"mount" them. To put this in simplistic terms, mounting means joining those 
drives to your 
file system. You do that using the mount command. Usually, you have to be 
root (the most 
priviledged user on a Linux system) to use the mount command. In BL, you run 
as root by 
default.

Linux treats everything as a file, including hardware like CD drives. dmesg 
is a program 
that shows you kernel messages--the messages you usually see scroll by on the 
screen as a 
Linux system boots. There's lots of helpful info in there about what the 
kernel detected as 
it booted. If you didn't catch it all as it whizzed by during system booting, 
you can see it 
all again once the system has booted by issuing the command "dmesg |less" 
("less" is a 
program that dmesg output is piped through and that lets you scroll back and 
forth; if you 
just issued dmesg, not using the pipe command and "less," you'd see only the 
tail end of the 
dmesg output, i.e., it would scroll past alot more quickly than it does as 
the system boots, 
and you would end up with only the last screenful in front of you).

To make this all relevant to what Sindi is saying here, she would like you to 
look at dmesg 
output so that you can see what device file the Linux kernel associated with 
your CD drive. 
As I said, Linux treats even hardware as a file. Hardware devices detected 
during the boot 
routine are assigned device file names. The names are found in the /dev 
directory. Hard 
drives and CD/ATAPI drives attached to IDE headers or expansion cards are 
assigned device 
designations hd[a-z]#: the a-z lettering designates where the drive is 
installed, i.e., 
whether it's on the primary, secondary, or some other IDE controller. hda 
represents the 
master drive on the primary IDE channel, hdb the slave drive on the primary 
IDE channel, and 
so forth. The # represents the order in which partitions appear on the given 
drive: 1-4 
represent primary partitions, while 5 and following represent extended or 
logical 
partitions. Thus, hda1 is the first primary partition on the master drive on 
the primary IDE 
channel, hda2 the second primary partition on the master drive on the primary 
IDE channel, 
and so forth. All these various hdx# files are found under the /dev directory 
and, depending 
on what the kernel detected as the system booted, some of those files will be 
associated 
with hardware on your system. Among dmesg output, you'll see something like

-------------------------------------
/dev/hdc: AOPEN CD-RW CRW4850 1.00 20020826, ATAPI CD/DVD-ROM drive
--------------------------------------

That will tell you what device file Linux has associated with your CD drive 
(/dev/hdc in my 
case). Note that CD drives don't have any partition number and simply end 
with a letter 
designation, not a number. _But_ you can't directly access the device file, 
as Sindi has 
indicated: you have to mount the device file to a mount point that exists (or 
which you 
create) on the system first. To do that, you issue the command

-----------
mount /dev/hdc /mnt
-----------

At that point, you can browse the contents of a CD, as Sindi notes below.

> Look for HOWTOS, and man pages in man format - and ignore the 
> tags.  Or get man2html from a Slackware package and gunzip and convert the 
> man pages, then read with links.  There is a discussion about this in the 
> archives if you want to make a script.

My own preference is to create a specific mount point for things rather than 
to use a 
generic one like the /mnt directory Sindi advises. It can happen on the 
scenario she 
outlines that you end up trying to mount more than one thing at that mount 
point (I've 
actually seen Sindi do this at one point), having forgotten something is 
already mounted 
there. This can lead to data corruption, system instability, and other 
undesireable 
occurences. I would therefore encourage creating a specific mount point for 
your CD 
drive--say, for example, at /mnt/CD. Once you've created that, then you'd 
issue

-------------
mount /dev/hdc /mnt/CD
------------

to mount your CD drive.

'Nuff said for now, I hope.

James

PS I don't know what Sindi means by "in man format" so I won't try to 
interpret that.