The boot up sequence of testbed
The figure below explains the interactive procedure among Orbit nodes, CMC and Console/Service after commands like "omf load [1,2] baseline-7.11.ndz" is executed. This command will turn on a node and load specified Frisbee image to the hard driver of the node. The detail is explained below.
- Node handler tells CMC to turn on the node through the CM.
- The node boots from the Ethernet port by default and tried to acquire IP address from DHCP server.
- DHCP and DNS server will assign IP address and corresponding host name for the node. DHCP also tells the node the address of Tftp server for PXE image.
- Node handler makes a symbol link for the PXE configuration file. The symbol link named as the IP address of the node indicates the node to fetch the correct PXE image file.
- The node downloads a small memory-based Linux kernel and file system from Tftp server.
- The node boots up with the memory-based Linux kernel and launches Node Agent. Meanwhile, Node handler deletes the symbol link.
- Node agent will inform Node handler after the initial boot up is done.
- Node handler launches Frisbeed server with specified Frisbee image file and tells Node agent to run Frisbee client.
- Frisbee client downloads a Frisbee image file and loads it to the hard driver.
- After the imaging process is done, Node handler will turn off the node.
- "omf" is the entry command for node handler.
- CM is installed on the PCI slot of each node. It is a simple, reliable, platform-independent subsystem for managing and autonomously monitoring the status of each node in the ORBIT network test bed.
- CMC is the only orbit service provided by Gridservice. Gridservice2 provides other orbit services.
- Frisbee is a fast disk-imaging tool with server/client mode. More information can be found in http://www.emulab.net/downloads/frisbee-README-20031021.txt[[BR]]
- Node agent and Node handler is used by Console to control orbit nodes to run programs or scripts on nodes.
- Services includes a couple of generic services, such as DHCP, and Orbit-specified services, such as Frisbee and OML.