Department of Computer Science

Machine Learning Research Group

University of Texas at Austin Artificial Intelligence Lab

Additional Storage

If you need to store a large amount of research data, there are several places available to you via UT resources, depending on your needs:

Group Shared Space in /u/ml

The ML group has disk space in /u/ml, which you must be a member of the group 'lunar' to access. If you're not in lunar, Ray will have to e-mail udb to get you added. You can check by typing 'groups' at the command line. This space is backed up and is redundant, and can be considered permanent storage. However, it is small (only 200GB) and fills up quickly -- it's often at 95% or more. To find out how much space there is, type df -h /u/ml at the command line. You can (and should) use condor to distribute the computation (see below) here.

A side note: on CS space that is backed up, such as your home directory and /u/ml, you can type "cd .snapshot" at any place to access snapshots of the current directory from each of the last 5 hours, the last 12 days, and the last 4 weeks. This can be a lifesaver when you've accidentally overwritten important files (although it is not a good substitute for a good source code revision control system, such git or SVN).

Notes on maintaining the /u/ml/ space

/u/ml is a file space that costs a lot of money - $200/10GB. We are not likely to expand it any time soon. There is a job assignment called 'Disk Space Czar' whose job it is to make sure that this space doesn't run out.

The directory mounted as /u/ml is actually only part of the ML Group's disk volume, /v/filer4b/v16q001, where the directory /v/filer4b/v16q001/ml is mounted on /u/ml. There is a disk utilization script in /v/filer4b/v16q001/ that you may find useful. There is a lot of stuf in the volume that was left over by previous students - please ensure no current student needs it before removing any of it.

/scratch/cluster on Mastodon

There is a large unbacked-up scratch disk accessible only on the Mastodon nodes. It is currently (October 2014) 24TB. To access it, you'll need to e-mail gripe and ask for Mastodon scratch space, which they will grant you by giving you a directory called /scratch/cluster/$USER. You cannot directly access these on your desktop -- instead, ssh into one of the Mastodon submit nodes ( and work from there, then submit jobs to condor with the line "requirements = InMastodon" to process them.

Each /scratch allocation has an initial 200GB quota. If you're working on a project and need more space, you can email gripe and ask for a temporary increase - they generally grant them liberally.

More about Condor and our cluster. If you use Condor heavily, it is very useful to make a script to help you submit jobs. Others have written much more complex systems that simulate MapReduce.

Local storage on your machine

You may also ask for local storage on your machine. E-mail gripe and ask them to make you a directory on /var/local/ on your machine. You may want to see how big that is by typing df -h /var/local. Depending on your machine, it will be about 40GB - 750GB. This space is not accessible at all through condor, and is not backed up, and may be lost on system upgrades, hard drive failures, etc. Gripe will send you a list of all the warnings about storage in /var/local when you request access.

Ray may also be willing to buy external hard drives that you can attach to your computer. This will give you a few TB of personal disk space, but it is not available on the network and is not backed up.

Other Resources

There are some resources available outside of the department, particularly through TACC and Matt Lease and Jason Baldridge's recent LIFT grant. TACC operates a variety of high performance clusters and has up to 6PB of storage. You can run Hadoop MapReduce jobs on some of these clusters, and there is a page describing the process. If you want MPI, this is your place. You may need to get added to an allocation for it, so talk to Ray, Matt, or Jason if you think this is your best option.

The computational linguists also operate a small cluster of machines that have some storage and maintain some corpora. If you are working with people in the linguistics department and would like access, contact Katrin or Jason. This cluster is currently without a real admin, and its future is not entirely certain. There is also a small Hadoop cluster (Markov) in CLA, with somewhere in the 12TB range of HDFS storage.

Last Update: July 5, 2013