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.

WWW: http://corvus.kek.jp/~manabe/pcf/dolly/