[linux-lvm] LVM rootfs and cramfs as ramdisk

[Jan H. van Gils]

	Hi,

First some thinks I found out.

When you create with lvmcreate_initrd the /boot/initrd-lvm-<kernel> file
the file is an ext2 filesystem. On a debian distro that wil give you problems
because the kernel expects a cramfs as ramdisk file.

Here is a work around I found :

mount the /boot/initrd-lvm-<kernel> file
mount -t ext2 -o loop /boot/initrd-lvm-<kernel> /mnt

copy the file to temporary working directory
cd /mnt; find . -print | cpio -udmp /var/tmp/lvm

dismount the /mnt file system and mount the kernel original
mount -t cramfs -o loop /boot/initrd.img-<kernel>
cd /mnt; find . -print | cpio -udmp /var/tmp/lvm

now create the new cramfs initrd file
cd /var/tmp; mkcramfs lvm/ initrd.cramfs
make sure the owner and group member are root <chown -R root:root initrd.cramfs)

To be sure you can check the initrd.cramfs with cramfsck -v initrd.cramfs.

Now I am wondering about one thing ? cramfs is a readonly filesystem
when the system boot it executes a vgscan and that creates a
"/etc/lvmtab" and "/etc/lvmtab.d" successfully created".

But because the cramfs is readonly, wil this not be an impossibility,
and is the cramfs ramdisk file not possible at all !!

Please responce on this subject.

Greetz, Jan


-- 
With regards Jan H. van Gils
Internet web-page http://www.VGNet.NL/
Internet e-mail address JanVG at VGNet.NL
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