Supercomputer Facility

The /scratch Directory

The purpose of /scratch is to provide a large amount of disk space with very high read/write speeds for those applications that need it. The /scratch directory is composed of 20 separate fibre channel disk drives, which are striped together to form one large filesystem. These disks are very fast, but they are also relatively expensive.

To get the most out of this resource, it must be kept clean so that space is available when needed. We do not want /scratch to be used for long-term storage. Therefore, we are running a program to REMOVE ALL FILES IN /scratch THAT HAVE NOT BEEN ACCESSED FOR 30 DAYS. This program is automatically executed by the system to keep /scratch clean.

Users will be warned by the program at least a few days before any files are removed. The warning message will list the files that will be removed, and it will be emailed to the user's hbar account. If you want this warning to be forwarded to some other address, you should create a .forward file on hbar to automatically forward your mail.

The program will NOT look at the temporary directories created by the queue system, so if your job uses these queue system directories, your files will not be erased until your job ends.

If you have a special need to keep certain files in /scratch for more than 30 days, please contact Paul Reed for a temporary waiver. Be prepared to justify your need.

A Note about Good Citizenship

This intent of this policy is to keep /scratch clean so that space will be available when needed. It is expected that users will be "good citizens" on this shared resource and adhere to the intent of the policy. Users may discover that it is possible to exploit the mechanics of the process and prevent their files from being erased. However, this type of behavior is NOT good citizenship, and it will not be tolerated.