File Storage

We provide a number of ways to store your files, each with its own advantages and disadvantages. This page will give you an introduction to the various places you can put your files and why you might use each.

Every user has a home directory, which is regularly backed up in case files are accidentally deleted. You have one home directory on the IBM pSeries systems and one on the Katana Cluster/Linux Cluster/Blue Gene. Your Linux home directory is accessible from the pSeries machines with the pathname /linux/$HOME. Similarly, your pSeries home directory is accessible from the Linux machines with the pathname /ibm/$HOME. You can apply here for additional home directory space.

Most of our systems (the Blue Gene is the exception) also have a fairly large /scratch partition. This space is intended for temporary (generally a week or less and automatically deleted after 10 days), not backed up, storage of your files. Since each machine has its own /scratch partition, this space is very fast to access when you use the local /scratch area to the machine your code is running on. Scratch space is shared by all users of the machines, so it may sometimes get full. Please be considerate of other users by deleting your files once you no longer need them.

Project disk space is available for those projects which need to store large data sets and get high speed access to that data. Project disk space may be requested by a project's principal investigator, if it is needed by his group. Some of the partitions are backed up regularly and all are reserved to your group, up to the amount of space you are granted. All of the /project file systems are accessible from all of our computing systems. However, note that this space is extremely expensive to buy and maintain (FAR MORE than disk on home PCs) and so is a limited quantity and we may not be able to allocate you as much space as you think you need.

We also provide access to a tape archive mass storage facility. This system allows you to write extremely large (or small) quantities of data to tape backup and retrieve it later. If you have a significant amount of space being taken up in either your home directory or /project space by files you do not need regular access to but wish to keep for the future, please consider writing them out to tape and then deleting them from your online space.