Provided by: lvm10_1.0.8-8_i386
lvmcreate_initrd - create an initial ramdisk to boot with root on a
lvcmreate_initrd [-i|--iop IOP] [-D|--devfs] [-v|--verbose]
lvmcreate_initrd creates a new compressed initial ramdisk /boot/initrd-
lvm-KernelVersion.gz. The initial ramdisk contains all necessary
binaries, shared libraries and a linuxrc file to switch to a logical
volume based root filesystem. To build an initial ramdisk for a kernel
other than the one currently running add the KernelVersion parameter
(e.g. lvmcreate_initrd 2.3.25) on the command line.
Print a usage message on standard output and exit.
-i, --iop IOP
Specify the LVM kernel IOP version if you are using wrapper
scripts in /sbin. This is only necessary if you are building an
initrd for a kernel other than the current one, and you have
tools for multiple IOP versions installed.
Force the use of devfs when building the initrd.
lvmcreate_initrd by default probes for devfs by checking for
/dev/.devfsd, which is created by devfsd when it is running.
This option will force lvmcreate_initrd to do this, when devfsd
is not currently running.
Gives verbose runtime information about the creation of the ram
Print version number and exit successfully.
The necessary actions to change your system into a "root on logical
volume" one are:
Create a small (~20MB) partition which is BIOS reachable to hold the
/boot filesystem (if you already have a small partition based root
filesystem this can be used instead). If you want to boot standalone
from this partition in an emergency, copy all the necessary binaries
and libraries to that filesystem as well and create a corresponding
/etc/lilo.conf entry. In order to be able to edit lilo.conf when booted
standalone, you should move /etc/lilo.conf to /boot/lilo.conf and
create a symbolic link to it in /etc. This is not needed if you have a
boot/root floppy which contains the LVM binaries and the library.
Create all logical volumes you need (for root, usr, opt etc.), create
filesystems in them, mount them and transfer all files from the
partition based filesystems into the logical volume based ones.
Set up your /etc/lilo.conf with a boot configuration like:
image = /boot/vmlinuz
initrd = /boot/initrd-lvm-KernelVersion.gz
root = /dev/YourVG/YourRootLV
label = rootonlv
append = â€â€™ramdisk_size=8192â€â€™
Replace YourVG and YourRootLV by your actual volume group and root
logical volume names. You also need to change the ramdisk size to be
at least as large as that reported while lvmcreate_initrd is run. If
you have enough memory, it is OK if the ramdisk size in /etc/lilo.conf
is larger than what lvmcreate_initrd reports (the memory is freed after
booting). Also, your /etc/fstab in the root logical volume should
contain entries for the root LV, and the boot partition, along with any
other LVs you have configured:
/dev/YourVG/YourRootLV / ext2 defaults 0 1
/dev/YourBootPartition /boot ext2 defaults 0 2
/dev/YourVG/YourUsrLV /usr ext2 defaults 0 3
/dev/YourVG/YourOptLV /opt ext2 defaults 0 4
You can use other supported filesystem types as well (e.g. reiserfs) if
you have support for those in your kernel. Run lilo, reboot and try...
The partitions containing the former /usr, /opt etc. filesystems can
now be used as physical volumes. Use pvcreate(8) to turn them into PVs
and then use vgextend(8) to add them to e.g. YourVG.
lvmcreate_initrd honours the TMPDIR environment variable when creating
the temporary filesystem. By default this will be in /tmp but you may
need to override this using TMPDIR if your /tmp is on a filesystem that
does not allow +loopback mounts (eg tmpfs).
lvcmcreate_initrd returns 0 for success. 1 is returned in all other
lilo(8), lilo.conf(5), fstab(5), lvm(8), pvcreate(8), vgextend(8),
Heinz Mauelshagen <Linux-LVM@Sistina.com>