[PLUG] Disk Drive Puzzlers

[Derek Loree]

Hi Guy,


On Thu, 2002-10-24 at 08:17, guy1656 wrote:
> At the last clinic, a kind soul helped me get Caldera 2.2 running on my 
> 233Mhz ATX box. We (mostly he) also installed a new HD. I got to learn a bit 
> about fdisk, fsck, looking in dmesg, editing fstab, and linking.
> 
> But not enough - when the 'new' disk drive DIED 4 hours later, I bought a 
> replacement (and this time NOT from Fry's...) 
> 
> Now I've been trying to install the new one myself with 4 Linux books for 
> company:
> Siever, "Linux in a Nutshell"
> Ball, "Teach Yourself Linux in 24 Hours"
> Wells, "Linux! I Didn't Know You Could Do That..."
> Welsh & Kaufmann, "Linux A-Z"
> 
> To derail any RTFM comments in the bud, I can state that NONE of these books 
> has an index entry for 'mount point.' This is a term I learned at the clinic, 
> and since it's missing from these books, we know that NONE of them have the 
> proper detail or organization to teach people how to install a new hard 
> drive. There's also no explanation for what the zeros mean in
> 
> /dev/hdb1 /mnt/hdb1 ext2 defaults 0 0 
> 
> or when you might want to use other digits. Anyways, I've had to run on 
> memory.
> 
> PUZZLER #1: The CHS numbers in the disk drive are different from what the 
> BIOS guesses if set to 'AUTO' (so I manually entered the CHS from the manual 
> into BIOS and left LBA as AUTO,) and then dmesg comes up with a third set of 
> numbers. Which ones are correct? 

It doesn't matter, the only thing that linux needs from the BIOS is to
start the boot process, once the kernel loads, it doesn't pay any
attention to what the BIOS says.  My suggestion is to leave it on AUTO
AUTO.
> 
> So we know that the new HD is being found, at least. Using the CHS numbers 
> from dmesg, I created two partitions and formatted them (I think - mke2fs?)
> 
> Now we're at that 'mount point' point. PUZZLER #2:
> 
> mkdir /mnt/hdb1?

This created your mount point.
 
> ln /dev/hdb1 /mnt/hdb1?

Linking won't work, block devices need to be "mount"ed to mount points:

mount /dev/hdb1 /mnt/hdb1

If this command fails, then you haven't formatted the drive, for that
use:

mke2fs /dev/hdb1

> ln -s?

The best kind of link, called a symlink, it is used to create files or
directories with more than one name, but only one real copy of the
data.  (For example, /usr/doc usually has a whole slew of symlinks to
/usr/share/doc)

> mkfs?  (So far this one says it's "not a block special device.")

See above
> 
> Lastly, PUZZLER #3:
> 
> I have a CDROM, a floppy and two hard disks, but ls mnt/ shows:
> 
> cdrom fd0 fd1 floppy floppy2  /hdb1* /hdb2*
>  
> (Of course, /hdb1 and -2 aren't working yet)
> 
> But what are fd0, fd1 and floppy 2?

At this point, they are just empty directories waiting for someone to
mount something to them.  So, for example, if you insert a CD, it will
most likely get mounted on /mnt/cdrom, which is where you will find the
contents of the CD.  For a list of mounted block devices, run the
command:

mount

without any arguments.

HTH

Derek Loree