[linux-lvm] booting a dm+lvm2 kernel

Luca Berra bluca at comedia.it
Thu Jan 1 17:40:01 UTC 2004

On Fri, Jan 02, 2004 at 12:10:11AM +0100, Christophe Saout wrote:
>I thought you were talking about the lvmcreate_initrd script that came
i actually never used lvmcreate_initrd that came with LVM1,

>Yes, I've seen redhat doing this. I personally prefer being able to
>override it at the command line though. Having something hardcoded in
>the initrd sounds strange to me.
i agree with your concern, i'll try to get it from the command line

>I have attached the script. I parse /proc/cmdline, try to remove root=
>using a shell function and if it actually removed something I know that
>the rest has to be a device name. :)
uhm, you should be wary of the case when a root= is in lilo.conf and
luser wants to override it from cmdline. you stop a t the first

>Wasn't ash the one from busybox?
no busybox is a dietlibc compiled shell that already has most command
compiled in, so a single executable, and smaller than glibc.

>With udev I just created /dev/console and some others. Doing everything
>from the script seems unnecessary.
i have to, because of tmpfs dev

>> My initrd detects if the root VG is on a md (softraid) device and
>> starts it before trying to activate the VG.
>Doesn't the kernel start them automatically? You mean, if it isn't
>activated in the kernel? Probably a good idea.
I strongly believe that raid autodetection should be done in user space,
possibly with mdadm. There is a big advantage in being able to control
what gets activated and when, besides distribution kernels use modular
scsi drive modules, so probably autodetection won't work anyway.
I also don't have the faintest idea if the kernel deals with stacked
raid devices

>Yes, that's also possible. But I don't really like it being readonly
>because, as you say, mounting something on /etc or /dev is unnecessary.
>What's the problem with ext2? The wasted memory?
wasted memory and disk space, being able to fit kernel+initrd on a
single floppy is a good reason

>I would love making the initrd an initramfs. But that doesn't currently
i think initramfs is not mature yet.

Luca Berra -- bluca at comedia.it
        Communication Media & Services S.r.l.
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