
LiveBackup boot options:


required boot options
======================

  lb_system=<SYSTEM> 
     => select system you like to boot

  System images are searched on the boot-media in the directory /system/
  unless you define to use a block device.
  Systems must be named according the lb_system=<SYSTEM> option. 
  Depending on what your kernel supports, you can have:

       <SYSTEM>.sqsh   compressed squashfs filesystem

       <SYSTEM>.img[:<mount-opts>]    a harddisk image, i.e. see qemu-img 

           without <mount-opts> it is assumed that the image contains 
           a partition table and the root-filesystem is on the 
           first partition. If this is not true you may
           define options like:

                  mount-opts=ro,loop,offset=<offset>

           if there is no partition table the offset is 0. 
           If you have a partition table the
           offset can be calculated from:

                   fdisk -fu <SYSTEM>.img  

           values by the multiplication:

                    offset=sector_size*partition_start

           if you specify options the actual mount command will be:

                mount  -o <mount-opts> <SYSTEM>.img /mnt/system


       <SYSTEM>.cloop  compressed cloop image

       <SYSTEM>/       a directory if the media itself is mounted 
                       with a valid root-fs like ext2/ext3

       /dev/<device>  use a read-only mount of a given device as 
                      root-filesystem 


choose a filesystem overlay technique (default is unionfs)
============================================================

  lb_unionfs[=<size root fs ram overlay> | auto[:<reserved ram size>] | <block-device>[:fstype[:pathspec]] ]
      => define overlay memory layout used with unionfs

     default values:  
                      <size root fs overlay> = 64M
                      <reserved ram size>    = 256M

           example: lb_unionfs=20M

                         will use 20M RAM overlay for rootfs

                    lb_unionfs=auto:320M

                         reserves 320M of RAM for OS, rest of
                         available RAM is used as rootfs overlay 

                    lb_unionfs=/dev/hda2

                         will use /dev/hda2 as writable filesystem layer
                         ( /dev/hda2 must be formatted with a 
                           valid filesystem )

                    lb_unionfs=/dev/hda2:ext3

                         will use /dev/hda2 mounted as ext3 filesystem

                    lb_unionfs=/dev/hda2:ext3:/home/overlay

                         will mount /dev/hda2 and use the directory
                         /home/overlay as writable filesystem layer
                         ( directory /home/overlay must exist )


  lb_aufs[=<size root fs ram overlay> | auto[:<OS reserved ram size>] | <block-device>[:fstype[:pathspec]] ]
      => define overlay memory layout used with aufs
         aufs is an alternate to unionfs 


  lb_dm[=<size root fs ram overlay> | auto[:<OS reserved ram size>] | <block-device>[:fstype[:pathspec]] ]
      => choose device mapper snapshot for overlay
         if you define a pathspec, it must point to a regular file instead of a directory


  lb_symlinks[=<size ramfs> | auto[:<OS reserved ram size>] | <block-device>[:fstype[:pathspec]] ]
      => use read only image with symbolic links to files copied to ram

         example:  lb_symlinks=32M


optional settings:
==================

  lb_config=<config_name>
     => use system startup configuration from config/<config_name> 
        instead default which is config/<SYSTEM> 

        lb_config=NO will disable startup system configuration

  lb_hwdetect=<hwdetect-script>
     => enable hardware detection. hwdetect-script may be any
     script/program which will be called before init will start.
     
     default: lb_hwdetect=not_set 
 
  lb_debug   
     => enable debugging mode
     => offers interactive shell before system boot

  lb_verify
      =>    system image is verified by its md5 sum during
            boot procedure

  lb_swap
      => search for partitions with linux swap signature, if
         found add an fstab entry

  lb_toram[=<size>]
      => if you have plenty of ram, copy all data so
         media can be removed

           example: lb_toram=20%
             if compressed image fits into 20% of memory then
             copy it to ram

           lb_toram=no will disable this feature

  lb_noeject
      => if possible unused media will be unmounted and ejected    
         this option reverts this strategy

  lb_device=<device>[:<fs>][:<path>]
      => if set then the specified device is search in first place.
         This option may speedup boot process and allows to boot 
         a LiveBackup from unusual devices. Example:

                   lb_device=/dev/sdb1:ext3

         if you have the LiveBackup master root directory in a
         subdirectory path, you may use:

                    lb_device=/dev/hda1:ext3:/opt/master-mybackup

  lb_console=<device>
      => redirect output from initrd scripts to device
           examples:
                    lb_console=/dev/ttyS0

  lb_NOcolor         
      => do not use colored output

  lb_verbosity=<n>
      => verbosity during LiveBackp start
         n=0  : display only critical errors
         n=1  : errors + warnings
         n=2  : errors + warnings + infos
         n>2  : all messages

  lb_isofile=<filename>
      => to be documented ........

  lb_xcmd=cmd
      => this is a hack to execute commands in a verly early boot
         stage, just after kernel modules are loaded. Example:

          lb_xcmd=mke2fs%/dev/hda2
 
         all blanks in command line have to be replaced by %
         characters to form a single token

   lb_rootdev=<major>:<minor>
      => if you need to define a special root device

   lb_skip
      => just load the kernel modules and continue on root device 


optional if you boot the LiveCD over network
============================================

  lb_address=<network-ip-address|dhcp>
     => network IP during network boot, this can differ from
        address assigned by the bootloader:
        (PXE, etherboot, grub-networkboot ...)
        and may be different to final network configuration after
        LiveBackup-System is up.

  lb_interface=<network-interface>
     => default is eth0

  lb_netmask=<netmask>
     => default is set to 255.255.255.0

  lb_gateway=<gateway-ip> 
          => default is set to 0.0.0.0 (default gateway)

  lb_nfsmount=<server:/path>
          => server and path to mount master directory by NFS

  lb_wget=<args-to-wget>
          => wget is used to retrieve the master-directory by network
             args-to-wget is a string passed to wget, all blanks have to
             be replaced by % characters. Example:

              "-r%ftp://10.123.64.75/pub/InstallerCD"

  lb_mastersize=<size>           
          => disk usage required to download the master-directory 
             (default 10M).

             The master-directory is loaded into ram, ensure your
             machine has enought of it. Size parameter is passed to
             mount (man mount), so it can have suffixes like K, M, G
             ...


HINT:

if you have build the initrd with INITRD_DISCOVER=yes option
you can discover your hardware inside the initrd shell
(i.e. started by lb_debug option), examples:

# lists everything:
LiveBackup> discover
   
# show modprobe commands to load modules:
LiveBackup> discover-show



