In administrating a large scale PC cluster, installation and updating both
of kernel and utility software to whole the system are very troublesome,
especially if the numbers of PC exceeds a hundred. In installation, people
usually make dead copies of a hard disk image in which software systems are
previously installed and then they are distributed among node PCs by CDs or
hard disk themselves.
Though some software do such a process through networks, they commonly have
an performance bottleneck at server where the original image are hold.
A cloning program `dolly' developed in ETH(Swiss Federal Institute of
Technology) avoids such bottleneck by using a "ring" type connection rather
than 'hub' type connection among one server and many clients.
I have extended its concept with multi-threading and pipeline technique.
It speeds up installation process very much. One-to-ten copying, for example,
finishes in almost same minutes for one-to-one copy.
In addition, time out sensing 'bypass' mechanism makes the copy process
pretty robust in the case of a client machine trouble.