Linux Solutions

Welcome to the tutorial guide. The guide will provide a user with advise and guidance on linear disk array device driver.

Please note that this driver lets a user combine several disk partitions into one logical block device. If a user use this, then his/her multiple devices driver will be able to use the so-called linear mode, i.e. it will combine the disk partitions by simply appending one to the other.

For example:
modprobe linear
There are no module parameters.
raid0: RAID-0 device driver
This driver lets a user combine several disk partitions into one logical block device.
If a user uses this, then his/her multiple devices driver will be able to use the so-called raid0 mode, i.e. it will combine the disk partitions into one logical device in such a fashion as to fill them up evenly, one chunk here and one chunk there. This will increase the throughput rate if the partitions reside on distinct disks.

For example:
modprobe raid0
rd: ramdisk device driver
A ramdisk is a block device whose storage is composed of system memory (real memory; not virtual). A user can use it like a very fast disk device and also in circumstances where he/she need a device, but don’t have traditional hardware devices to play with.

A user can have his/her boot loader (e.g. lilo) create a ramdisk and load it with data (perhaps from a floppy disk). Please note that a user cannot use the LKM version of the ramdisk driver because the driver will have to be in the kernel at boot time.

A ramdisk is actually conceptually simple in Linux. Disk devices operate through memory because of the buffer cache. The only difference with a ramdisk is that a user can never actually get past the buffer cache to a real device. This is because with a ramdisk, 1) when he/she first access a particular block, Linux just assumes it is all zeroes; and 2) the device’s buffer cache blocks are never written to the device, ergo never stolen for use with other devices. This means reads and writes are always to the buffer cache and never reach the device.

There is additional information about ramdisks in the file Documentation/ramdisk.txt in the Linux source tree.
An example is provided below:
Modprobe rd
There are no module parameters that a user can supply to the LKM, but if he/she bind the module into the base kernel, there are kernel parameters a user can pass to it.

XT disk device driver
This is a very old 8 bit hard disk controllers used in the IBM XT computer. No, the existence of XT disk support does NOT mean that a user can run Linux on an IBM XT :).
For example:
modprobe xd
There are no module parameters.

If you followed advise and guidance as provided in this tutorial guide then you would have learnt about disk device driver.