fstab files from other installations

**Tortoise** · 05-30-2003, 07:25 PM

Hurrah!
I appreciate the handholding, but don't want you to have to do this for everyone who is having trouble getting their head round this - if I have a few moments I may try to do this myself so we have it from an idiot's persepective - it seems fair to contribute in this way, since it was my problem that was solved.

**rickenbacherus** · 05-30-2003, 08:15 PM

Originally Posted by Tortoise

Also, how to I delete spurious mountpoints? rm tells me they are not files, so I can't delete them. I'm guessing there is a corresponding directory delete command.

Code:

man rm

**rickenbacherus** · 05-30-2003, 08:27 PM

Originally Posted by Tortoise

Great, that works, and I have desktop shortcuts too, although I can't unmount the drive from the desktop? Seems odd, but I suppose that's because I'm not root. Is there an easy way to be root temporarily from the KDE GUI?

Code:

man chmod

**Stephen** · 05-30-2003, 09:05 PM

Originally Posted by Tortoise

Great, that works, and I have desktop shortcuts too, although I can't unmount the drive from the desktop? Seems odd, but I suppose that's because I'm not root. Is there an easy way to be root temporarily from the KDE GUI?

Check for user in the line refering to the drive in the /etc/fstab. If the user is in there you should be able to access and umount the drive from the desktop icon there is no need to mount it as root.

**Tortoise** · 05-31-2003, 04:41 AM

Originally Posted by senorian

Dear rickenbacherus
You posts are always educational but this thread is very, very clear and detailed.
Please keep on with the good work AND, if at all possible, collect and collate your various instructions and post so that one can search them. There is a tremendous amount of very poorly written (i. condensed) Linux info on the web.
We, the newbies of the world, desperately need a lot more of your quality instructions.
Many thanks

Maybe this will help, feel free to edit it if you feel like it.
Tortoise

The following is a condensed summary of advice given by Rickenbacherus, Stephen and Aay to Tortoise, a linux newby having trouble getting to grips with CDRW / DVD drives under Knoppix. Senorian suggested that it might be useful to post this in an easier to use fashion. I am grateful for the assistance of these folks, but errors are my own. Tortoise.

Tortoise's problem was caused by him not understanding the relationship between the name that Knoppix gives to each drive by default, and the arbitrary mount points that the user allocated to each drive. He was distressed that while the CD edition correctly identified all his hard drive partitions, and his CDRW/DVD, as well as his CD/DVD drive, the hard disc install seemed to do none of this, and, indeed, put icons on the desktop which produced errors when they were clicked.

It turns out that you can mount any of your drives to any mount point you like, example:
mount /dev/hda1 /mnt/stupid
As long as you have a mount point named 'stupid' it will mount there.
A mountpoint is simply a directory inside /mnt/
You can see what mountpoints you have by opening a shell and typing:
cd /mnt
ls
This gives you the contents of the directory /mnt, which are your mountpoints, that is to say, the place in your directory structure where these drives will be mounted.
You can make new ones (call them whatever you like for the moment, but see below for conventions on naming):
mkdir /mnt/cdrom
This should create a mountpoint called cdrom, you may get an error if you already have a mountpoint called that.
Type:
cd /mnt
ls
again, and you should see the new mountpoint there. Of course, now you have to mount something there, and you have to know what the thing you want to mount is called. You can mount anything to any mountpoint, but you are most likely to want to mount your drives to a relatively descriptive mountpoint for clarity.

The place where this matching up takes place is in the file /etc/fstab, the FileSystemTABle. Open this as root (if you intend to edit it) by going to the K menu, and opening a shell as root, you will need to enter the root password to do this. The type:
kedit /etc/fstab
to open the file in kedit

Let's say your fstab looks like this:
# /etc/fstab: filesystem table.
# filesystem mountpoint type options dump pass
/dev/hda1 / ext3 defaults,errors=remount-ro 0 1
/dev/hda2 none swap sw 0 0
proc /proc proc defaults 0 0
/dev/fd0 /floppy vfat defaults,user,noauto,showexec,umask=022 0 0
/dev/cdrom /cdrom iso9660 defaults,ro,user,noexec,auto 0 0

# signs mean comment, and the computer will ignore anything coming after them. If there is a # in front of anything, bear in mind it will do nothing.
The first part ('/dev/hda1' in the example above) is the block device or filesystem you want to mount. This is the name that linux gives to your device. The second part – '/' is the mount point that fstab will mount (e.g. /dev/hda1) to. As I said, you can mount any filesystem to any mount point.
Another example: '/dev/cdrom' is the block device- '/cdrom' is the mount point but if '/cdrom' doesn't exist then it can't be mounted there right? So we need to create mount points for all the devices listed in the /dev/ secions, as above.

In case the drives are not listed in the fstab, and to take a look at what linux thinks you have connected in the way of cdrw/dvd drives, you'll need to use SCSI emulation. Since you booted the Knoppix cd and installed it I'm sure it is already set up that way. Do this:

cat /proc/scsi/scsi

Now you should see your cdrw drives. Actually you'll see everything on the SCSI BUS.

0,0,0 - CDRW
0,1,0 - DVD

(Those are just examples- your mileage may vary) You can call your drives anything you like which makes things a lot easier. Here's how:

ln -s /dev/scd0 /dev/cdrw

Translated literally ln link -s symbolicly/dev/scd0 the actual name of your cdrw /dev/cdrw the name of your new symbolic link.

Now for the test to see what /dev/cdrw really points to do this:
ls -al /dev/cdrw

It should now indicate that /dev/cdrw is actually nothing more than a symbolic link to the actual device of /dev/scd0

Now look closely at your fstab- the format is like this:

filesystem mountpoint type
So, applying that to the following line from your fstab

/dev/cdrom /mnt/cdrom iso9660 defaults,ro,user,noexec 0 0

/dev/cdrom is your filesystem
/mnt/cdrom is your mount point
iso9660 is the type
But if you don't have /dev/cdrom OR /mnt/cdrom, you just need to make the symbolic link to your cdrom like this:
ln -s /dev/scd0 /dev/cdrom
ls -al /dev/cdrom
This should show you want /dev/cdrom is really pointing to now. Next make sure that you have an appropriate mountpoint to mount it on:
mkdir /mnt/cdrom
cd /mnt
ls
...and if everything above went smoothly now fstab will mount /dev/cdrom (which is actually /dev/scd0) on the mount point /mnt/cdrom.

If everything above went smoothly......
As root, do this:
mount -t auto /dev/cdrom
cd /mnt/cdrom
ls
You should see whatever it is that's on the disk. Now do this:

cd
umount /dev/cdrom

Notice that it is not uNmount- there is no n- it's umount. You should always remember to umount anything that you have mounted. How do you find out what's mounted?--You already know:

mount

How do you umount everything?

umount -a

Don't worry- it won't umount anything that's in use by the system.
Also let me remind you that you cannot mount an audio cd because it has no filesystem on it. Additionally, you can't mount an empty drive because ... ...there's no filesystem in an empty drive either. So anytime you want to mount a cdrom you need to have a data cd in the drive.
Repeat the above for each drive you are trying to set up, with the appropriate names for each one. Call the mountpoints whatever you like, but bear in mind that many programs expect the naming convention /cdrom or /dvd.
Next up, you may want to create desktop icons for these:
As an aside, harddrive icons can be created easily by running:
rebuildfstab -r as root
and then mkdesktophdicons as a normal user.
First off, delete any spurious icons that may be there, they will only sow confusion. Then,
right click on the destkop and select "Create New" and then "CD/DVD-ROM Device"
Select the "Device" tab at the top.
From the pull down menu select your CD/DVD device (in the case above it would be /dev/cdrom.
Click "Ok" at the bottom of window and then your icon should be on the desktop and working.

Ok – you should be away!

**rickenbacherus** · 05-31-2003, 02:55 PM

Originally Posted by senorian

Please keep on with the good work AND, if at all possible, collect and collate your various instructions and post so that one can search them.

Gee wouldn't it be nice if someone could do that?

Check this out. WikiWiki

"A WikiWikiWeb is a site where everyone can collaborate on the content. The most well-known and widely used Wiki is the Portland Pattern Repository at................"