[torqueusers] Passwordless_ssh on a diskless cluster

Gelonia L Dent gdent at amnh.org
Mon Apr 28 09:48:29 MDT 2008


Dear All,

I am trying to eliminate using password login between the headnode and
compute nodes on a diskless cluster. I've using the following steps:

____________________
On head:
ssh-keygen -t rsa         (didn't enter a pass phrase)
ssh-copy-id -i ~/.ssh/id_rsa.pub nodeN   (for a subset of the nodes
(N=0,126))

On compute nodes
ssh-keygen -t rsa
ssh-copy-id -i ~/.ssh/id_rsa.pub master
______________________

I have three issues:
First, I did this on ten nodes, then something happened and I had to
restart the sshd daemon, now I've lost connection to those ten nodes
completely. I think my authorized_keys file got overwritten when I
restarted ssh. How can I reach these nodes again?
      Error message/       ssh: connect to host node10 port 22: No route
to host

Second, the first time I attempted this (before I broke those 10 nodes) I
neglected to copy the same id_rsa.pub file to all the nodes and was
generating a different one for each node. I've since corrected that step
and am copying the same *.pub file from the head to all the nodes, then
generating a *.pub from each node to the head. This gives me
bi-directional access between each node and the head, but not between
nodes. Do I need passwordless access between nodes for Moab/Torque to work
properly? If so, how can this be accomplished.

Third, today I am attempting again to go through this process. I have 128
nodes. Is there a parameter in the sshd_config  file that is set to use
passwords across the nodes which I may have overlooked. If so, can it be
used to set a 'no password option' permanently between the head and
compute nodes.

Any ideas would be greatly appreciated.

Best,

--
Gelonia Dent, PhD
Manager of Scientific Computing
Invertebrate Zoology
The American Museum of Natural History
(212) 313-7911





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