Chapter 9. Controlling the system
The controlling the system chapter details commands that you may wish to use to interact with devices on your system and then details how to control processes and services/daemons.
- eject
eject simply tells a device to open (eject) the drive. Useful for cdrom/DVD drives.
For example the command below would eject the cdrom-drive (if your cdrom is linked to /dev/cdrom):
eject /dev/cdrom
This won't work unless: This will only work if the user has permission to mount the partition. Please see the tip in the Section called Mounting and Unmounting (Floppy/CDROM/Hard-drive Partitions) for more information.
Mounting and Unmounting (Floppy/CDROM/Hard-drive Partitions)
Allowing Users to mount partitions: By default a UNIX system will allow normal users to unmount partitions. However unless given permission by the superuser, users will not be allowed to mount partitions.
The commands listed below will not work for normal users unless users have permission to mount that device.
If your particular distribution is setup not to allow users to mount partitions its not very hard to change this, simply edit the /etc/fstab file (as root) and:
Replace the word "defaults" with "user" orAdd "user" to the end of the options list for the particular partition(s).
- mount
Mount a device. Attach the device to the file-system hierarchy (the tree ( / )). This needs to be done so you can access the drive (see below, the Section called Mounting and Unmounting (Floppy/CDROM/Hard-drive Partitions) for an example).
- umount
'Unmount' a device. The command umount (no 'n') unmount's a device. It removes it from the file-system hierarchy (the tree ( / )). This needs to be done before you remove a floppy/CDROM or any other removable device (see below, the Section called Mounting and Unmounting (Floppy/CDROM/Hard-drive Partitions) for an example).
- smbmount //wincomp/c /mnt/win
Where “win” would be the place you want it mounted and “wincomp” is the IP address or name of your windows computer.
Please note: Using ping/smbmount/ssh or other UNIX system programs with a computer name rather than IP address will only work if you have the computer listed in your /etc/hosts file. Here is an example:
192.168.1.100 new
This line says that their is a computer called “new” with IP address 192.168.1.100. Now that it exists in the /etc/hosts file I don't have to type the IP address anymore, just the name “new”.smbmount is a tool from the samba package, it can mount a remote windows file-system onto your current computer.
Un-mounting uses the same syntax as 'umount', as listed above, or you may like to use:
smbumount /mountpoint
Here are some more examples of how to mount a file-system:
mount -t ext2 /dev/fd0 /mnt/floppy
mount -t iso9660 /dev/hdb /mnt/cdrom 
mount -t iso /tmp/image_file /mnt/iso_file/ -o loop 
The -t option: On any system running a newer version of the Linux kernel the -t option is not always necessary and can be left out.
Examples of how to unmount a file-system (necessary before you eject/remove disk):
umount /mount_point
An example unmount point could be “/mnt/floppy” or “/mnt/cdrom”