SDB:Mounting, Partitioning, and Configuring File Systems

Version: 1.0 -

Under Linux, several file systems and file system types (e.g. ext2, minix, msdos, vfat ,iso9660) can be combined to form a large overall file system under /.

Since Linux does not have logical drives such as e.g. in DOS (C:, D:, etc.), this mechanism is necessary. The Linux system regards all physical drives, including hard disks, floppy drives, CD-ROM drives, MO, ZIP drives, etc. as file systems that are integrated in the parent file system /.

This procedure is called mounting. The act of detaching a file system from the / file system is referred to as unmounting.

Prerequisites for including and mounting file systems:

• A known file system must exist on the respective medium (CD, MO, ZIP medium) or partition (hard disk); this corresponds to the formatting process. The file system type must be one that is supported by the command mount.
• There must be a point where the file system can be mounted on the "/" file system. This point is called mountpoint and is usually an empty directory that needs to be created with mkdir.
• The type of the file system that is going to be mounted must either be stated together with the command mount or entered in the file /etc/fstab.

File systems that are regularly mounted (e.g. when the system is booted) are listed in the file /etc/fstab, each line representing one file system. For more information on this issue, please check the respective manpages:

        man fstab
        man mount

Accordingly, an entry for an ATAPI CD-ROM drive (master on the second controller) could look as follows:

        /dev/hdc   /cdrom  iso9660   ro,noauto,user 0   0

This allows all users to mount CDs by entering "mount /cdrom". Please pay attention to the sequence of the file systems in the list. The sequence in the file /etc/fstab should correspond to the subsequent mounting sequence.

The correct sequence is usually determined by YaST; for example, /usr/local is mounted after /usr. The command mount can not determine the correct sequence and mounts file systems in the order of their appearance in /etc/fstab.

The options user and noauto are interesting for the use of mount and /etc/fstab:

user allows a file system to be mounted/unmounted by any user (this is especially interesting for the CD-ROM drive).

noauto prevents the indicated partition from being mounted automatically at system start-up (i.e. mount -a), and requires an explicit manual mount. This is useful for media that may not always be available at system start-up (e.g. CD-ROM). <keyword>partition,filesystem,fstab,etc,mount,automount</keyword>