You may install ICTCE to a shared folder on the master node. Just keep in mind that shared libraries will be loaded from network resource at application run time.
Users need to have passwordless ssh setup to be able to use Intel MPI Library. It should not be a problem if users have their home directories on compute nodes mounted to an NFS share. In this case just configure ssh that way so you will be able to login from a node to itself without a password. For instance, for openSSH you will have in the ~/.ssh directory the secret key and a public key saved in the authorized_keys file.
When building a diskless image please consider proper DAPL configuration. Having a latest dapl package may be a good idea.
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You may select two different installation modes. For the Intel Cluster Studio 2011 (ISC) you may select either Current node installation type or All cluster nodes installation type. Selection may be done by choosing the Change advanced options installer menu item. ISC (former ICTCE ) installer will attempt to write data to the remote nodes only if you select All cluster nodes installation type.
Once you have diskless systems your choice should be current node installation type. You need either install software to NFS share or incorporate it to the system image that you use for your diskless systems.