Where are my drives?

Linux shows all the directories in one directory tree, irrespectively of what drives/hardware they are found on. Generally, this is a much better solution than the traditional DOS/Windows model--it completely abstracts the file system from the underlying hardware. You will appreciate this if you ever have to re-arrange or expand your hardware or add network resources. But for the users who are accustomed to the DOS way of dealing with drives, it adds some extra complexity.

To be brief, don't search for drive letters. There are none under Linux; the content of your disks appears as subdirectories on your single Linux filesystem (directory tree).   On default, the content of removable media does not appear automatically in these subdirectories--you have to "mount" your drives. See the next answers for details. You should also unmount a drive before ejecting the media.

You can access (read and write) a variety of drives and file systems from under Linux. This includes native Linux partitions, DOS and MS Windows partitions (on hard drives or floppies), ZIP and Jazz drives, and CDROM disks. Many less common file system types are also supported. This means that you can download your Linux software using Netscape for Windows, save the downloaded file on your MS Windows hard drive partition, and then boot Linux and copy the downloaded software from the Windows partition on your harddrive to the Linux partition, and finally install the software under Linux.

How can I access my CDROM?

Mount it. The mounting adds all the directories and files from your CD to your Linux directory tree so you can easily access them without the drive letter.

As root, you can mount the CDROM with a command like this:

mount -t auto /dev/cdrom /mnt/cdrom

If this works, the contents of your CD appears in the directory /mnt/cdrom

Chances are this command will not work for you right away--you may have to customize it. Here is how it works.

The command tells the operating system to mount a filesystem autodetecting the filesystem type ("-t auto"). The device is /dev/cdrom. The mountpoint (the directory where to which "mounting" takes place) is /mnt/cdrom. This directory must exist and be empty. If it does not exist, create it with:

mkdir /mnt/cdrom

If the mounting command fails, make sure that the device /dev/cdrom exists. If it doesn't, where is your CDROM? Chances are it is something like /dev/hdb if you have an IDE CDROM. Try /dev/hdb instead of /dev/cdrom in the mount example above. If this fails, you can try /dev/hdc or /dev/hdd, if your cd is an IDE CDROM. If none of them is your CDROM, maybe you don't have IDE but a SCSI CDROM? Then try /dev/sda1, /dev/sda2, etc. ["hda" is the the primary IDE master drive, "hdb" is the primary IDE slave drive, "hdc" is the secondary IDE master (if you have two IDE interfaces on your computer), hdd is the secondary IDE slave, "sda" is the first SCSI interface and the number is the SCSI device id number.]

It is a good idea to have a device /dev/cdrom anyway because some programs assume that it exists. If it does not exist on your system, you may create it as a symbolic link using, for example:

ln -s /dev/hdb /dev/cdrom

if your cdrom is the /dev/hdb drive.

If you cannot mount because "the device is already mounted or directory busy", perhaps the mountpoint /mnt/cdrom is your current directory. You have to change the directory to somewhere else in order to be able to mount to it; for example change the current directory to the root directory by issuing this command:

cd /

To unmount a mounted CD, exit the directory /mnt/cdrom and type as root:

umount /mnt/cdrom

Your CDROM may refuse to eject the media if it is not unmounted. Also, you may have problems mounting the next CD if the previous one was not unmounted. If you cannot unmount because "the device is busy", perhaps /mnt/cdrom (or any subdirectory underneath) is your current directory? You need to change your current directory to somewhere else out of the mountpoint in order to unmount the device.