Load Linux kernel module before SCSI module using mkinitrd

last updated in Categories Linux, Sys admin, Tips

Today I have discovered nifty mkinitrd command option ๐Ÿ™‚

mkinitrd command is use to make an initrd image. According to man page:
The mkinitrd script constructs a directory structure that can serve as an initrd root file system. It then generates an image containing that directory structure using mkcramfs(8), which can be loaded using the initrd mechanism. The kernel modules for the specified kernel version will be placed in the directory structure. If version is omitted, it defaults to the version of the kernel that is currently running.

So mkinitrd creates an initial image used by the kernel for preloading the block device modules such as IDE, SCSI RAID etc. These modules are needed when system need to access the root filesystem.

If you have new SCSI card you need to make sure that a particular kernel module will be loaded by my initial ramdisk. Pass –preload option to mkinitrd to load the `module’ module in the initial ramdisk image. The module gets loaded before any SCSI modules which are specified in /etc/modprobe.conf. This is quite good if you need any module before SCSI module.
# mkinitrd --preload=module-name /boot/initrd-2.6.9-42.ELsmp.img 2.6.9-42.ELsmp

Replace module-name with actual module name.

For more information read mkinitrd man page:

  • man mkinitrd

Posted by: Vivek Gite

The author is the creator of nixCraft and a seasoned sysadmin, DevOps engineer, and a trainer for the Linux operating system/Unix shell scripting. Get the latest tutorials on SysAdmin, Linux/Unix and open source topics via RSS/XML feed or weekly email newsletter.

1 comment

  1. I have same problem: I’ve installed FC7 on a machine with SATA disk. I’ve copy this machine (with ghost) to a machine with scsi disk. Now the machine boots but cannot find the scsi module during init. I’ve run mkinit with
    –preload=mptspi but It looks that this module isnt loading during the init process. What am I doing wrong? Thanks for the advice!

    Have a question? Post it on our forum!