Getting Started with Computing
Computing in the Hydrology Research group is done primarily on the LINUS operating system (CentOS). LINUX can be a challenge to learn, but it's a powerful and flexible computing platform. To get started, you might want to try reading O'Reilly's "Learning the UNIX Operating System" by Jerry Peek. There are also a number of decent tutorials online.
Research Computing
The large majority of processor time and disk space is used for research compute jobs. All resources are shared, so it is important to be able to run compute jobs and access memory efficiently in such a way that others can also do their work.
The following points are important:
- CPU & MEMORY
- DISK STORAGE
Keep an eye on your processes including how much CPU and memory they are using. The "top" command is very helpful for this. It displays the processes which are using the most system resources, and how much CPU & memory they are using. Keep in mind that "top" itself consumes resources and should only be used to check on your processes, not run constantly.
Most systems have 8 processors, so for these machines, a steady load of 8 is okay. This means that on average 8 jobs are on the processors. When the load goes higher, a great deal of efficiency and compute cycles are lost to switching jobs on and off the processor.
Keep an eye on your disk space usage. Given the large models we work with, it is quite easy to consume vast amounts of disk space. The "du" utility is very useful for this. It can give a disk usage summary for files and directories. It is best to always use the -h flag because it gives a more readable output. The NAS (network access storage) system is NOT backed up. For information on backups and best practices for file organization, look here.
