Powerwall setup

Note: the powerwall was not upgraded from the 3rd Ed. to the 4th, it has been taken out of service for the time being as the machines are slow (100Mhz) and those in the center tend to overheat. Functionally has been largely replaced by the faster cluster machines

Setup of the IBM Thinkpad 760E's as cpu servers required some changes to the pccpcdisk file in order to add support for graphics and pcmcia. Our cpurc . is also modified to include sections from termrc inorder to run rio on the cpu server.

These nodes have a non standard disk layout to support a 1.4G root filesystem(kfs) as well as a 500Mb cache filesystem(cfs) and nvram, the partition layout is:

 disk/prep /dev/sdC0/plan9
  9fat                  0 20482      (20482 sectors, 10.00 MB)
  fs                20482 3000000    (2979518 sectors, 1.42 GB)
  cache           3000000 4032880    (1032880 sectors, 504.33 MB)
  nvram           4032880 4032881    (1 sectors, 512 B )
  swap            4032881 4128705    (95824 sectors, 46.78 MB)

The nodes are setup to use a cfs disk cache, the plan9.ini which supports this and booting off of the fileserver by default. old plan9.ini using kernel on local disk:

	bootfile=sdC0!9fat!9pccpud
	bootdisk=local!#S/sdC0/fs
	bootargs=il
	cfs=#S/sdC0/cache
	*nomp=1
	distname=plan9
	partition=new
	ether0=type=EC2T
	monitor=xga
	vgasize=1024x768x8	
	mouseport=ps2

new plan9.ini using kernel from fileserver:

	bootdisk=local!#S/sdC0/fs
	bootargs=il
	cfs=#S/sdC0/cache
	*nomp=1
	distname=plan9
	partition=new
	ether0=type=EC2T
	bootfile=ether0
	monitor=xga
	vgasize=1024x768x8	
	mouseport=ps2

The bootfile arg tells the machine that it will get it's kernel using bootp/tftp over the network from the auth server. The auth server knows which kernel to send based on the bootf arg in /lib/ndb/local in this case it is /386/9pw

cloning

All the powerwall machines are clones of the same basic setup to make a clone we insert a extra hard drive into the 760 floppy/cdrom bay using an adapter made for this purpose. boot the machine off its disk by typing "local" at the boot prompt and then dd the drive using:

	dd -if /dev/sdC0/data -of /dev/sdC1/data -bs 5000000

sync the disks, power down the machine and remove the secondary disk and insert it into the clone.

building the Powerwall

The initial 6 cpu servers

The base from a discarded shipping crate was just the right side for mounting the powerwall on. We drilled holes for each power cord and network cord and the used velcro and rivets to attach the power supplies to the back of the crate.

The custom bent network "dongle" that fits into the hole left by the removal of the thinkpad modem. This allow the machines to be placed side by side.

The front of the crate, with the power cords, network dongles and velcro attachments in place, following a suggestion by John "man-beast" Patchett, each piece of velcro is riveted to the crate.

Installing the nodes. Each power cord fits into the hole left by the cdron/floppy bay, and each network dongle fits into the modem port. The piece of paper is used under the node to keep the velcro from sticking until the node is in position.