Hardware

Our cluster consists of 24 machines, including one storage and management server, 20 Dell R220 servers, and 3 Dell R730 servers. They are connected by a Dell N4000 10Gb ethernet switch. The configurations are as follows:

• 1 Management node:
• Hardware: 4-core, 16GB of memory, two 3TB disks as a mirror (RAID 1), and 1Gb ethernet
  
• Name: node-ops.cse.ohio-state.edu from outside, headnode from inside
• Usage: this node serves as a proxy node between the department's network and our internal network. Any user should log into this node first and then log into other nodes (R220s and R730s). This node also serves as a storage server for all source code and papers.
• Note: DO NOT run experiments on this node.

• 20 Dell R220 servers:
• Hardware: 4-core, 16GB of memory, two disks, and 1Gb ethernet
• Name: node220-1 to node220-20
• Usage: for normal experiments
• Note: DO NOT store important data on these nodes.

• 3 Dell R730 servers:
• Hardware: 16-core, 64GB of memory, 8 disks, one SSD, and 10Gb ethernet
• Name: node730-1 to node730-3
• Usage: for experiments that require high speed network or SSD
  
• Note: DO NOT store important data on these nodes.

• 1 Dell N4000 Switch
• Hardware: 48 10Gb ports. Enough bandwidth even if all connected machines are running at 10Gb/sec.

Usage

If you are interested in becoming a user of this cluster, please send me an email with your preferred username and your Google account. I will create the user for you and email you a temporary password. Then you can first "ssh node-ops.cse.ohio-state.edu" with your username and password. After that you can ssh to any R220 or R730 nodes without passwords.

• Choose a strong password. Machines with weak passwords do get hacked.
  
• Your home directory is shared among all nodes by NFS. You can put your source code there. However, the shared NFS directory is usually slow, so if your experiment needs storage, you'd better use local disks.
• You are granted sudo priviledges on all R220s and R730s. Please be very careful when operating with sudo. You are not granted sudo on the management node. If you really need to do something special on the management node, please email me.
• If you need to install a software, please first try to install it in your own home directory without sudo. This will minimize its impact on other users. Sometimes it is not possible and if you have to install a software with sudo, please 1) install it on all machines and 2) document it at /share/install_history so that we can keep track of it.
• Similarly, you are allowed to modify kernels or change OS parameters with sudo, but do document it at /share/install_history. If you don't need those modifications any more, please change them back.
• Please reserve your machines at Google calendar (I will add your account to that calendar). Leave your name and phone number for emergency contact. No mechanism is enforcing you to follow your reservations, but processes without reservation can be killed without notifying.
  

Resources

• Your home directory in /users is shared among all machines. There is no quote on your home directory, so do delete unnecessary files.
  
• The /share directory is also shared among all machines. This directory is supposed to store files that are valuable to the whole group. Examples include trace files, benchmarks, papers, etc. DO NOT store anything without proper copyrights.
• An svn repo is created. The root directory is svn+ssh://node-ops.cse.ohio-state.edu/projects/svn/repos. All users have read access. Please email me if you need write access.
• Your home directory and /share directory is stored on a mirrored (RAID 1) disk on the management node. Do backup your important files (source codes, papers, etc) at other places in case the management node is destroyed, but be careful don't make those files public.