Sysadmin
This is the hub for the CS sysadmins on the wiki.
Overview
If you're visually inclined, we have a colorful and easy-to-edit map of our servers here!
Server room
Our servers are in Noyes, the science building that predates the CST. For general information about the server room and how to use it, check out this page.
Compute (servers and clusters)
We have CS and cluster machines.
CS machines:
- bowie: hosts and exports user files; Jupyterhub; landing server
- smiley: VM host, not accessible to regular users
- web: website host
- net: network administration host for CS
- code: GitLab host
- auth: host of the LDAP user database
Cluster machines:
- hopper: landing server, NFS host for cluster
- bronte, pollock, lovelace: large compute servers
- layout, wachowski: clusters of multiple nodes linked together through a switch and managed through a headnode
- meier, miyamoto, sakurai: backup servers
- monitor: server monitoring
We have spare nodes on the old al-salam cluster’s rack. These should be used for services that can handle minutes to hours of downtime, as they only have one power supply.
Specialized resources
Specialized computing applications are supported on the following machines:
- GPU’s for AI/ML/data science: layout cluster
- virtualization: smiley
- containers: bowie
Network
We have two network fabrics linking the machines together. There are three subdomains.
10 Gb
We have 10Gb fabric to mount files over NFS. Machines with 10Gb support have an IP address in the class C range 10.10.10.0/24 and we want to add DNS to these addresses.
1 Gb (cluster, cs)
We have two class C subnets on the 1Gb fabric: 159.28.22.0/24 (CS) and 159.28.23.0/24 (cluster). This means we have double the IP addresses on the 1Gb fabric that we have on the 10Gb fabric.
Any user accessing *.cluster.earlham.edu and *.cs.earlham.edu is making calls on a 1Gb network.
Intra-cluster fabrics
The layout cluster has an Infiniband infrastructure. Wachowski has only a 1Gb infrastructure.
Power
We have a backup power supply, with batteries last upgraded in 2019 (?). We’ve had a few outages since then and power has held up well.
HVAC
HVAC systems are static and are largely managed by Facilities.
See full topology diagrams here.
A word about what's happening between files and the drives they live on.
New sysadmins
These pages will be helpful for you if you're just starting in the group:
- Welcoming a new sysadmin
- General troubleshooting tips for admins
- Sandbox Notes
- Password managers
- Server safety
- Ticket tracking for current projects
Note: you'll need to log in with wiki credentials to see most Sysadmin pages.
Additional information
These pages contain a lot of the most important information about our systems and how we operate.
Technical docs
- Ticket tracking for current projects
- Server safety
- Backup
- Monitoring
- SSH info relevant to admins
- User Management and LDAP generally
- Jupyterhub and NBGrader
- Email service
- Xen Server
- Network File System (NFS)
- Web Servers and Websites
- Databases
- DNS and DHCP
- AWS
- Bash startup scripts
- VirtualBox
- X Applications
- Cluster Overview and additional details
Common tasks
- Recurring tasks - e.g. software updates, hardware replacements
- Contacting all users
- Reset password
- Software installation
- Installing software under modules
- Add a computer to CS or cluster domains
- Supporting senior projects
- How to do a planned shutdown and reboot of the system
- Testing services (after a reboot, upgrade, change in the phase of the moon, etc.)
- Upgrading SSL Certificates
- Launch a process at startup
