Orinoco - IBMI Webserver

What your admin wants to tell you about our storage and how he thinks it should be used.

Repono est omnis divisa in partes duo...

The whole storage is divided into two parts, a file system where the home directories are stored and another file system where the scientific data the group works with is stored.

Home Directories

The home directories (/home/<username>) are provided by three independent export servers that use NFS with Kerberos.

NFS is mountable by any computer on the Computer Science (CS) department network. This is important for compatibility reasons:

Users can log in from outside the CS network using SSH gateways provided by the CS department.
Students (and of course staff) can use their account with their IBMI home directory on any computer connected to the CS user management system. Even on non-IBMI group computers.
Kerberos ensures that only the authenticated user can access your home directory and encrypts the connection between the system you are working on and the export server with time-limited "tickets".

Group Directories

The group directories are usually mounted on each computenode or cluster managed by IBMI IT. You can find them here: /ceph/ibmi/<short name of the group>.

The computer you are working on authenticates to the storage system and opens an encrypted network connection.
Access is granted through the file system's access control lists (ACL). It is NOT Kerberos.
This file system is the faster one. It connects directly, without export servers and Kerberos, etc., and the metadata is stored on faster disks (for those who care about such things).

What to do with this information?

I hope you share my view on this storage system that it's a good idea to store everything that belongs to your account (profiles, configurations... and maybe a few small documents) in your home directory that only you can access from any computer on the CS network. Scientific data that should perhaps be accessible to others (colleagues, students, supervisors...) should be stored in the group directories, where they can also be accessed much faster. No ticket-time-limit will interupt your calculations.