We help IT Professionals succeed at work.

How to install Linux

dustybryn asked
Can anyone give me a step by step guide to installing red hat 4.2 linux onto a pentium 3. I'm having problems with terminology eg. 'mount point'?
Watch Question

It sounds like you are currently a Windows user so mount points are a new concept.

Under Windows you have a disk letter for each physical hard disk (C: D: E: etc) and you can partition a physical disk into a number of logical disks which each get a drive letter. Under each drive letter you then have a directory tree so you identify a directory with a combination of the drive letter and then the directory under that c:\foo\bar

Under Linux (and other Unix'es) there is no concept of a drive letter. The entire file system exists as a tree under a top level directory called / (note the directory slashes are forward under unix not backwards as per Windows). The file system includes everything about the machine, all hardware (ports, memory, cpu etc) is represented by a file within the file system.

A mount point is the "connection" of all or part of the file system to a physical disk device.

Lets assume you have one physical disk for the time being.
It is entirely possible to allocate the entire disk area (with the exception of the swap space) to the root or / directory. Linus will then build its directory tree under the / directory within the disk.

The upside of this is that you don't have to allocate space for different directories, the downside is that any directory within the tree can grow to the point where it takes up the entire disk.

Alternatively you can allocate separate mount points of a fixed size for various directories. You could allocate, say, 400 MB for the /home directory and the remainder for /.

In this case the contents of /home can only ever grow to 400 MB and the rest of the disk is unaffected. The downside is that if you find you need more than 400 MB for /home you have some reasonably tricky work to do to expand the /home area. Some Unix'es can expand directories (such as AIX) but Linux can't at present.

Mount points can't currently cross physical disks so if you have two hard disks you need to allocate some of the file system to each disk. Let say you have 2 x 2 GB disks.

You could allocate / to the first disk and /home to the second or any other layout you choose.

You also need to allocate a swap space somewhere, generally this should be 2 x the amount of physical memory you have. This is not a standard ext2 file system.

The Linux installer should allow you to graphically allocate the disk space. As a first time user, assuming you have 1 disk device I think the easiest thing to do is allocate the following mount points

/boot   50 MB
swap    2 x RAM amount
/       the rest of your disk.

All your hardware devices will then appear in the /dev directory. Your floppy disk will appear at the following mount point /dev/fd0 so you would address the floppy as /dev/fd0.

Your cdrom would also appear in the same directory, generally as /dev/cdrom - which is an alias to the real file representing the cdrom.

The installer should create the mount points for you and will put them in a file /etc/fstab which will contain the mount point, the hardware file for the mount point and the properties of the mount point.
The hard disk mount points in /etc/fstab are generally mounted whenever the system is booted.

Removable devices (floppy disk, cdrom etc) have to be mounted prior to use and they have to be dismounted after use or when swapping media - this is most important. Unlike Windows you can't just insert a cdrom and use it then remove it.

Some versions of Linux run an automounter that does this for you when the media is inserted and removed. IF this is not running then you would do the following to access a cdrom for example.....

1) Insert the media in the drive
2) As root type mount /dev/cdrom
3) You can then access the contents of the cdrom under the /mnt/cdrom file directory (cd /mnt/cdrom, ls -al etc)

To dis-mount the media you do the following.
1) Ensure no-one is using the device
2) As root type umount /mnt/cdrom (note umount not unmount)
3) Remove the media

If you get a message saying the device is busy it means that someone is using the device - you may have a session currently with the cdrom as its current directory.

Hope this gets you started.
Cheers - Gavin


Thanks very much for this Gavin it's really helpful.

Explore More ContentExplore courses, solutions, and other research materials related to this topic.