Prerequisites / Misc hints
If you use UDP-Cast to duplicate OS installations, all participating
machines should be rigorously identical
- Their hard disks should have the same size and layout (sectors,
heads, cylinders). Number of sectors and heads of source system should
stay identical, whereas number of cylinders of target system only be
greater or identical. N.B. If you are only transferring Linux
partitions (no other system), there is no need for matching sectors
and heads. Only the overall size of the target system must be equal or
bigger than that of the source system.
- Any peripherals (network cards, keyboards, mice) should be identical.
- If the template machine (sender) has more peripherals (such as
for instance a CD-Rom drive) than the client machines, their drivers
should be uninstalled before the multicast.
- See also the notes on special
notes about copying Windows machines
Note about copying to hard disks with different geometry:
- If the new disk (or partition) is bigger, the copied system won't
actually make any use of the additional space. In order to do that,
you need to resize the partition using a partition resizing tool such
as Partition Magic or PartEd
- When copying a linux system to a partition or disk with differing
geometry, be sure to use the linear option in
/etc/lilo.conf. If for some reason you can't use this, be
sure to rerun lilo on the target system after the copy (boot from a
- Chose the proper duplex mode: if your network has a Hub, use
--half-duplex, if it has a switch, use
--full-duplex. If the network is mixed (central switch, hubs
around), use --half-duplex
- If you have a switch:
- enable "IGMP snooping".
- If hubs are connected to your switch, disable flow control on
the ports to which the hubs are connected. Disable flow control is
also necessary (on all ports where udp-senders site) if IGMP
snooping is not available or not working correctly.
- Disable Broadcast Storm Control (or else the switch might
consider the udpcast session as a broadcast storm, and slow it
- If too many retransmissions happen in full-duplex mode,
consider lowering the slice size using the --slice-size
option (default is 112).