How to Move a WN temporarily from the T2 to the MSU T3

This procedure can be used to temporarily move a WN from the T2 to the MSU T3. It leaves the WN in place in the T2 Rocks DB, but with bogus Mac addresses so that the T2 Rocks head node will not respond to a PXE request from the moving WN.

It should be easily reversible when the WN is moved back to the T2

On msurx6 do the following after determining the mac, etc, for the machine to be moved. Add to table. Then (where the original mac was 00:21:9b:8a:12:75, etc):
  • rocks set host interface mac cc-106-6 eth0 ff:21:9b:8a:12:75
  • rocks set host interface mac cc-106-6 eth1 ff:21:9b:8a:12:77
  • rocks sync config
  • rocks set host boot cc-106-6 action=install

Note this changes the first octet from 00 to ff, but does NOT wipe the config from the DB. Later, we'll reverse this when the machine is to move back from the T3 to the T2.

On msut3-rx6 then, I have a sub-dir called /root/Feb2016_tmp and there I've created a template file and a shell script, to take the info gleaned from msurx6, and from our desired destination machine, as placed in order in the spread sheet, and create a script to make the new, desired rocks commands that will create the new machine.

  • cd /root/Feb2016_tmp
  • ./make_new_cc.sh 113-42 00:21:9b:8a:12 75 77 8 129.15 237.15 eth
  • rocks remove host cc-113-42
  • bash -x ./cc-113-42.sh
  • rocks sync config

Now, reboot the old machine, and it will PXE when it comes round from msut3-rx6, but, the disk size is wrong, so, only PXE one of these at a time, as, once it starts to ping, from msut3-rx6 you will need to:
  • ssh -x -p 2200 cc-113-42
  • df -h (wait until all the /dev/sda partitions are mounted)
  • dd if=/dev/zero of=/dev/sda bs=4096 count=10000
  • reboot

Then, the second time around, the partition sizes will be correct.

BUT BEWARE! MAKE SURE YOU ARE REALLY ON THE WN HERE, AND NOT ON THE ROCKS HEADNODE. If you dd to /dev/sda on the rocks head node, then we are screwed.

book-keeping:
  • On a UM interactive use cluster_control to set the T2 machine name to power OFF
  • On green use cluster_control to set the T3 machine name to power ON

Sample table.

Old slot New slot First Mac eth0 Mac eth1 Mac Cores Private IP Public IP Nic Type
106-6 113-42 00:21:9b:8a:12 75 77 8 129.15 237.15 eth
117-14 113-36 00:22:19:66:25 ec ee 16 129.21 237.21 em

-- BobBall - 06 Feb 2017
Topic revision: r1 - 06 Feb 2017 - 14:51:25 - BobBall
 

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