Prerequisites / Misc hints

Pre-requisites

If you use UDP-Cast to duplicate OS installations, all participating machines should be rigorously identical hardware-wise. Most notably:

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

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 rescue disk).

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 down...)
- If too many retransmissions happen in full-duplex mode, consider lowering the slice size using the --slice-size option (default is 112).