How is initrd used in lilo.conf stanzas and what's it's purpose?

How is initrd used in lilo.conf stanzas and what's it's purpose?

Post by mike » Sun, 31 Dec 1899 09:00:00



Hi,
    I see the following stanza in the lilo.conf file:

initrd=/boot/initrd-2.0.34-0.6.img

       What is the meaning / significance in this line?

     I have seen multiboot lilo.conf files where there is
    only one stanza like this in the whole file. Not one
    for each distribution stanza that one wants to multiboot.

      Should there be an initrd statement for each distribution?

      Is it optional?

      Where does the initrd.img come from?

Thanks

Mike

 
 
 

How is initrd used in lilo.conf stanzas and what's it's purpose?

Post by Randy Coope » Sun, 31 Dec 1899 09:00:00


Mike,

There are at leat two manual pages you should read:
  mkinitrd
  conf.modules

initrd stand for initial ram disk. It is used to pre-load block device
modules (such as a SCSI module) which are needed to access the root file
system at boot time.

For example,  I have set up a floppy that allows me to boot and access
the root file system on a SCSI zip disk using a SCSI controller card
that contains no bios. This allows me to use the zip diskette as a
rescue disk. I don't use this anymore as now I simply boot from a CD if
I need a rescue disk.

I think that these days that initrd in conjenction with
/etc/conf.modules is mostly used as a convenient way to load modules at
boot time.

You should be aware that this facility is not standard on all Linux
distributions. It is standard on Redhat but not on Slackware.


> Hi,
>     I see the following stanza in the lilo.conf file:

> initrd=/boot/initrd-2.0.34-0.6.img

>        What is the meaning / significance in this line?

>      I have seen multiboot lilo.conf files where there is
>     only one stanza like this in the whole file. Not one
>     for each distribution stanza that one wants to multiboot.

>       Should there be an initrd statement for each distribution?

>       Is it optional?

>       Where does the initrd.img come from?

> Thanks

> Mike

--


 
 
 

How is initrd used in lilo.conf stanzas and what's it's purpose?

Post by Robert Helle » Sun, 31 Dec 1899 09:00:00



  In a message on Sun, 24 Sep 2000 14:45:47 GMT, wrote :

m> Hi,
m>     I see the following stanza in the lilo.conf file:
m>
m> initrd=/boot/initrd-2.0.34-0.6.img
m>
m>        What is the meaning / significance in this line?

initrd == Initial RamDisk.

        The system needs to load driver modules in order to mount the
real root file system.  This is the most common case and is in fact the
standard thing that 'modern' distros do for SCSI-based systems.

        Generally, a initial ramdisk is used when the kernel needs some
sort of 'disk' *before* it gets to the real hard disk (if any).  There
are several cases:

        This is a rescue boot disk -- this would be for a boot floppy.
The ramdisk contains the drivers and utilities needed to repair a broken
hard drive file system.

        This is for a diskless system and the ramdisk disk IS the system
(root) file system.

m>
m>      I have seen multiboot lilo.conf files where there is
m>     only one stanza like this in the whole file. Not one
m>     for each distribution stanza that one wants to multiboot.

This can be normal.  Some distributions have kernels with the SCSI
driver built in.  Some distributions create an initial ramdisk, even if
one is not needed and others create the initial ramdisk conditionally.

m>
m>       Should there be an initrd statement for each distribution?

Depends on the distribution and the system.

m>
m>       Is it optional?

It can be.  *Some* people re-build the kernel and  'compile in' the SCSI
driver(s) -- this saves a small amount of boot time at the expense of a
larger kernel.  When this is done, the initial ramdisk is not needed.

m>
m>       Where does the initrd.img come from?

See 'man mkinitrd'

m>
m>
m>
m> Thanks
m>
m> Mike
m>
m>                                                                                                  

--
                                     \/


http://www.deepsoft.com              /\FidoNet:    1:321/153

 
 
 

1. lilo can't find /etc/lilo.conf, even though it's there

Greetings,

I don't know how, but somehow when I try to update lilo and I run
/sbin/lilo, I get the message:
/etc/lilo.conf: No such file or directory

I run 'file /etc/lilo.conf' and it confirms that the file is there and
nothing else is unusual about it.

Running lilo -v only shows the credits to the author then prints that same
message.

Running lilo -C /etc/lilo.conf gives the same message.

I've verified that all files I refer to within lilo.conf are valid.

I've also put "garbage" at the first line of the file and gotten no error,
which makes me think that lilo really isn't able to open the file for some
reason.

Anyone have any idea what could be causing this?

Thanks much,
-Nick

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