Initializing diskless and dataless clients

Diskless and dataless clients are not installed in the same way as standalone machines. Instead, they are initialized. Initialization of diskless and dataless clients involves several phases of operation.

Item Description
Resource Allocation The resources required to support a diskless/dataless client must be allocated to the client before or during the initialization operation.

If the resource is a parent directory of client directories, the allocation will create an empty subdirectory for the client. The client subdirectory is then NFS-exported to the client. The client subdirectories are not populated until the initialization is actually performed.

Client Initialization The dkls_init and dtls_init operations are used in NIM to initialize the resources for client use.

Among the operations performed during client initialization are the following:

  • The boot image is made available to the client for performing a network boot.
  • If a root resource is used instead of a shared_root resource, then the root files, which are used for machine-specific customization, are copied into the client's subdirectory in the root resource. The files that are copied into the client root directories come from the SPOT resource that has been allocated to the client.
  • The /tftpboot/ file is created on the boot server (which is the SPOT server). This file contains information that will be needed by the client during the start-up configuration processing to successfully configure as a diskless or dataless client.
    The following are some of the variables defined in the file:
    export NIM_CONFIGURATION=diskless
    export RC_CONFIG=rc.dd_boot
    export ROOT=Host:Client_Root_Directory
    export SPOT=Host:SPOT_Location
    The paging location is set in the client's root directory in the /etc/swapspaces file.
Network Boot of the Client The client machine is booted over the network using standard bootp procedures for the machine type. The client obtains the boot image and begins running a mini-kernel in a file system in RAM.

The client tftp's the file from the /tftpboot directory on the SPOT server. The information in the file is used to properly configure the client as a diskless or dataless machine.

The dump is configured once the client is running if a dump resource is allocated to the client machine.

The remote file systems are mounted from the resource servers.

If the client is a dataless client, and no paging, tmp, home, or shared_home resource is allocated, then the client will create the missing file system on the local hard disk.