FACeWiki

Virtual Machine

Once you have created your VM, you can administrate it.

• To connect the VM as root:

$ stratus-connect-instance id

• To install packages (example with a VM running Scientific Linux):

root@vm $ yum install gcc-gfortran make gnuplot

• To create Smith user (only key pair is allowed for connexion):

root@vm $ useradd smith
root@vm $ su smith
smith@vm $ cd
smith@vm $ mkdir .ssh
smith@vm $ touch ~/.ssh/authorized_keys
smith@vm $ chmod 600 ~/.ssh/authorized_keys

Put the ~/.ssh/id_rsa.pub of Smith (local) in ~/.ssh/authorized_keys (VM).

• To connect as Smith:

$ ssh -i ~/.ssh/id_rsa smith@ip

If error appends (Permission denied (publickey).), clean the local known_hosts file:

local $ vi ~/.ssh/known_hosts

onevm-XX.lal.in2p3.fr ssh-rsa ...

• To transfert files (from MV to local):

$ scp -i ~/.ssh/id_rsa smith@ip:Rep/*.txt .

Virtual Cluster

• To create a Virtual Cluster, you need to run a specific disk image including NFS and ip6tables.
• To use the OpenMPI MPI library, you need to export binaries and libraries in your VM shell:

PATH=/usr/lib64/openmpi/bin
LD_LIBRARY_PATH=/usr/lib64/openmpi/lib

• To take back the user's key pair:

$ scp root@ip:/home/smith/.ssh/id_rsa* .

• To obtain informations on the cluster nodes:

root@vm $ cat /etc/hosts
# Cluster nodes
134.158.75.1 vm-1.lal.stratuslab.eu master
134.158.75.2 vm-2.lal.stratuslab.eu worker-0
134.158.75.3 vm-3.lal.stratuslab.eu worker-1
134.158.75.4 vm-4.lal.stratuslab.eu worker-2

root@vm $ cat .shosts
vm-1.lal.stratuslab.eu root
vm-2.lal.stratuslab.eu root
vm-3.lal.stratuslab.eu root
vm-4.lal.stratuslab.eu root

• To obtain informations on the MPI configuration file:

root@vm $ cat /tmp/machinefile 
134.158.75.1 slots=1
134.158.75.2 slots=1
134.158.75.3 slots=1
134.158.75.4 slots=1