Solaris Jumpstart: Remotely installing Solaris OS over network, probably in many systems simultaneously.
-Possible to install an OS on many systems together, thus saving time and effort.
-OS can be installed on selected set of clients based on their configuration.
-No need to be physically present at the system(Client) to install the OS.
-The saved OS image can be patched or upgraded.
-Installation using Jumpstart is faster than it is from CD.
-Client(s) : System(s) on which the OS has to be installed.
-Boot server : Used to boot the client so that the installation process could start.
-Install server: Contains the OS image to be installed.
-Configuration server: Contains rules and profiles. Also contains sysidcfg file which provides information during installation which otherwise would've to be manually entered by the user e.g. timezone, terminal type, locale, etc.
A single system can, and often does, act as all the servers.
Assuming the OS image is in the Install server and everything is set, Jumpstart works like this-
User gets console access to the client(s) e.g. from a tip server, and issues command “boot net – install” at the 'ok' prompt (on Sparc systems) which starts the process:
-The client sends an RARP request on the subnet.
-The Boot server has in.rarpd running, so it responds with the Client's IP address.
-On getting its IP address, the client sends out a tftp request for boot kernel image.
-The Boot server responds with the boot image.
-Client sends bootp request.
-Boot server responds with the client's info from /etc/bootparams file which contains information about Install server.
-Client gets root partition, install configuration and OS image from Install server and Solaris installation begins.
Boot server and Client should be on the same subnet. Since the Client sends an RARP request in the beginning to get its IP address, the Boot server has to be on the same subnet as the Client, as RARP requests genereally don't cross a router. So, Boot server and Client should be on same side of the router. 'ifconfig -a' of both Boot server and Client gives their IP address and netmask values. AND their respective IP address and netmask to find the subnet. If it is same for both the Boot server and Client, then it is fine.
In the future, I will discuss how to set up Boot and Install servers, various files needed for Jumpstart installation, and more advanced options like custom probes.