Best of Technical Support

Our experts answer your technical questions.
Problem Upgrading the Kernel

I'm trying to upgrade to kernel 2.2.5. When I type mkinitrd /boot/initrd-2.2.5.img 2.2.5, the system returns:

mount: the kernel does not recognize /dev/loop0 as a block device
Can't get a loopback device

What should I do? What has gone wrong? —Mun Hon Tham,

For some reason, automatic module loading is broken (you could do modprobe loop to load the module by hand). I am willing to bet you installed all the updates from the Red Hat FTP site, including the new modutils from the 2.2 directory. Unfortunately, modutils has a completely broken kerneld that causes the message you are seeing. I do not know why Red Hat hasn't taken that broken package off their FTP site. In the meantime, all you need to do is downgrade to the previous modutils by typing:

rpm -U --force modutils-version.i386.rpm

—Marc Merlin,

Cylinder Question

The Installation guide says the partition that contains /boot must be below cylinder 1023. My hard drive has 1400 cylinders. How do I find out which cylinders are not being used and if /boot will fit below cylinder 1023?

I will be using a dual-boot system with a DOS partition. My hard drive is 10.9GB and DOS/Windows is the primary partition, using 4.5GB. Can you help? —Jason Hipsher,

The most important factor that slips up new users is LBA mode drives. Logical Block Addressing translates cylinders into heads, dividing one by two and multiplying the other by two, so the numbers still work but you have fewer cylinders.

The problem is that with a 10GB drive, you most likely do not have 1400 cylinders. You probably have far more, and LBA is enabled on your drive (this is done in your BIOS and is normally enabled by default). You cannot turn it off without reloading your DOS/Windows partition.

You may be able to use the “linear” addressing feature in LILO to get around this problem, but it doesn't always work. A neat trick I use to get around the issue is to create a small (8MB is usually more than enough) partition at the very start of my drive to store my kernels. You may need PartitionMagic or some other partition-manipulation tool to do this without loss of data, but it will give you a place to store files that is guaranteed to be lower than the 1024th cylinder. You can then mount this at boot time (I put it under /img), so you can store your kernels there. Linux itself can be anywhere on the drive. —Chad Robinson,

Using the installation's fdisk (or disk druid), create the partitions you will need with the first one for DOS/Windows. Then separate a small (64-128MB) partition for swap and the rest for Linux. When you finish your installation, make sure you pick “MBR install” for LILO. —Mario Bittencourt,

X Windows vs. X11

What, if any, is the difference between X11 and X Windows? It seems as though both terms can be used interchangeably, but at the same time, it seems as if they are different servers. Is X Windows a shell or server on top of X11, or are they entirely different? I am not talking about look and feel, but the basic meaning. —Chris,

The terms are often used interchangeably, which can be confusing. The “official” name for X is “The X Window System”. Some purists get irritated when people say “X Windows”, but it's usually safe to say “X”.

You are actually talking about the same program. What's different is that the first term (X11) refers to the specific version of X. You're actually missing part of it—an Rx is usually included after it. For example, X11R5 refers to a popular and still commonly seen release. X11R6 is what most new Linux distributions are shipping with now (in the form of XFree86, an open-source distribution of X). —Chad Robinson,

Another X Question

When I type startx, the response I get is:

X11TransSocketUNIXConnect : Can't connect: errno = 111
giving up
xinit: Connection refused(errno 111) unable to connect to X server
xinit: no such process(errno 3) server error

Now, this is kind of irritating—I have used XF86config, but it doesn't seem to have the driver for the SIS6215 (4MB RAM). We have had X up, but only after we made some adjustments—we could view it in only 16 colors. Since this is just the 2.0.36 kernel, is there a chance that I must upgrade it? Do I need to get the XFree3.3.3 version to get this thing alive? (The school's hardware is a P166, SIS6215 videocard, Digital screen.) Do I have to reconfigure everything, or maybe install the new kernel and XFree version? —Mathias Bakkejord,

The newer the X version you use, the better your chances of finding a driver designed for your card. Upgrading your Linux kernel won't help here, although there are other good reasons to do so.

However, you can probably get your card working in at least 256-color mode by using the SVGA driver. This is a good idea anyway, since it will give you a chance to learn what the clock rate and refresh settings for your card and monitor need to be. It would be a good idea to try this before trying to find a specific driver for your card. —Chad Robinson,