Changes between Version 7 and Version 8 of Software/eAM/ePXE


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Timestamp:
Jan 11, 2013, 1:01:37 AM (12 years ago)
Author:
seskar
Comment:

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  • Software/eAM/ePXE

    v7 v8  
     1== PXE Aggregate Manager ==
    12
    2 Go back --> [wiki:Documentation] --> [wiki:Documentation/orbit-pxe Orbit-PXE]
    3 
    4 == Loading Orbit-PXE ==
    5 
    6 Whether you are imaging a node, saving a node image or doing inventory control Orbit nodes get orbit-pxe image loaded first into RAM. The way this is accomplished is by having the PXE server make a symbolic link of the node's IP address in hex to the orbit-pxe configuration file on the TFTP server. By default PXE configuration is to have the node boot off its local hard disk.
    7 
    8 /tftpboot/pxelinux.cfg/default
     3PXE Aggregate Manager configures tftp service to enable network loading of the ram based image that is used for imaging (boath loading and saving of the disk images) on the node. Once ram based image (orbit-pxe) is loaded it runs Resource Controller (RC) that will wait for the appropriate commands from the Experiment Controller (EC). The PXE AM will, on demand from EC (or any other AM) make a symbolic link of the node's IP address in hex pointing to the appropriate (inventory based) configuration file on the TFTP server. By default PXE configuration is to have the node boot off its local hard disk as specified in /tftpboot/pxelinux.cfg/default :
    94
    105{{{
    … …  
    1510}}}
    1611
    17 When orbit-pxe is to be loaded the nodehandler first tells the PXE server to set the symbolic link up to the orbit-pxe configuration. It does this by issuing an http GET request to the the following URL:
     12=== Usage Example ===
     13
     14Experiment controller (EC) issues:
    1815
    1916{{{
    20 http://pxe:5012/pxe/setBootImage?img=<image name>&node=<node ID>&ip=<ip address of node>
     17http://pxe:5054/pxe/setBootImage?node=node1-2.sb8.orbit-lab.org
    2118}}}
    2219
    23 The PXE server in turn creates a symbolic link for the respective IP address in hex. For example, if the node has an IP address of 10.18.1.2 (the case of sandbox8, node1-2) the respective IP address in hex is 0x0A.12.01.12 and as such its symbolic links' filename will be 0A120112.
     20The PXE AM in turn, queries the inventory AM to find out what is the approrpiate boot configuration for node1-2, and creates a symbolic link for the respective IP address in hex pointing it to a returned configuration file. For example, if the default boot configuration is obrit-2.0.0 and the node has an IP address of 10.18.1.2 (the case of sandbox8, node1-2) the respective IP address in hex is 0x0A.12.01.12 and as such its symbolic links' filename will be 0A120112.
    2421
     22{{{
    2523/tftpboot/pxelinux.cfg/0A120112 --> orbit-2.0.0
     24}}}
    2625
     26The configuration file specifies kernel and disk layout...
    2727{{{
    2828DEFAULT boel
    … …  
    3636}}}
    3737
    38 The specific version of orbit-pxe that is to be symlinked to is controlled by the nodehandler. After the symbolic link request the nodehandler will the reboot the node and based on this example the node will then load linux-orbit-pxe-2.6.20.4 with initramfs-orbit-pxe-2.0.0.gz as its initramfs cpio archive. The kernel then boots and finally calls /etc/init.d/rcS:
     38After the symbolic link request was created, the EC will the reboot the node and, based on this example, the node will load linux-orbit-pxe-2.6.20.4 with initramfs-orbit-pxe-2.0.0.gz as its initramfs cpio archive. The kernel then boots and finally calls /etc/init.d/rcS:
    3939
    4040{{{
    … …  
    7878fi
    7979cat /.orbit_image
    80 # Start nodeagent
    81 nodeagent4&
     80# Start omf-resctl-5.4
     81omf-resctl-5.4&
    8282}}}
    8383
    84 After this nodeagent will just wait until nodehandler issues it further commands.
     84After this RC will just wait until EC issues it further commands.