Running Linux, 5th Edition - Matthias Kalle Dalheimer [43]
The system reports out-of-memory errors while attempting to boot or install the software
This problem relates to the amount of RAM you have available. Keep in mind that Linux itself requires at least 8 MB of RAM to run at all; almost all current distributions of Linux require 32 MB or more. On systems with 16 MB of RAM or less, you may run into trouble booting the installation medium or installing the software itself. This is because many distributions use a ramdisk, which is a filesystem loaded directly into RAM, for operations while using the installation medium. The entire image of the installation boot floppy, for example, may be loaded into a ramdisk, which may require more than 1 MB of RAM.
The solution to this problem is to disable the ramdisk option when booting the install medium. Each distribution has a different procedure for doing this. Please see your distribution documentation for more information.
You may not see an out-of-memory error when attempting to boot or install the software; instead, the system may unexpectedly hang or fail to boot. If your system hangs, and none of the explanations in the previous section seems to be the cause, try disabling the ramdisk.
The system reports an error, such as "Permission denied" or "File not found," while booting
This is an indication that your installation boot medium is corrupt. If you attempt to boot from the installation medium (and you're sure you're doing everything correctly), you should not see any such errors. Contact the distributor of your Linux software and find out about the problem, and perhaps obtain another copy of the boot medium if necessary. If you downloaded the boot disk yourself, try re-creating the boot disk, and see if this solves your problem.
The system reports the error "VFS: Unable to mount root" when booting
This error message means that the root filesystem (found on the boot medium itself) could not be found. This means that either your boot medium is corrupt or you are not booting the system correctly.
For example, many CD-ROM/DVD distributions require you to have the CD-ROM/DVD in the drive when booting. Also be sure that the CD-ROM/DVD drive is on, and check for any activity. It's also possible the system is not locating your CD-ROM/DVD drive at boot time; see "Hardware Problems" for more information.
If you're sure you are booting the system correctly, your boot medium may indeed be corrupt. This is an uncommon problem, so try other solutions before attempting to use another boot floppy or tape. One handy feature here is Red Hat's new mediacheck option on the CD-ROM/DVD. This will check if the CD is OK.
Hardware Problems
The most common problem encountered when attempting to install or use Linux is an incompatibility with hardware . Even if all your hardware is supported by Linux, a misconfiguration or hardware conflict can sometimes cause strange results: your devices may not be detected at boot time, or the system may hang.
It is important to isolate these hardware problems if you suspect they may be the source of your trouble. In the following sections, we describe some common hardware problems and how to resolve them.
Isolating hardware problems
If you experience a problem you believe is hardware related, the first thing to do is attempt to isolate the problem. This means eliminating all possible variables and (usually) taking the system apart, piece by piece, until the offending piece of hardware is isolated.
This is not as frightening as it may sound. Basically, you should remove all nonessential hardware from your system (after turning the power off), and then determine which device is actually causing