Imager Personal Disk Usage Policy

created: June 21, 2010

modified: July 12, 2010

The Imager lab provides members a flexible amount of network-accessible, good performance, backed-up filesystem space, through the /ubc/cs/research/imager mount. Typically Imager-related files are stored either in a subdirectory of imager/project or imager/people.

The subdirectories in imager/project are organized by research project, with one or more faculty supervisors in control of the space. This is the recommended location for Imager-associated research projects. Files and directories here should in all cases have permissions set appropriately to allow the supervisor to read/write: nothing private should ever be stored here, though the use of UNIX groups may restrict access to an appropriate subset of people if desired. Tech staff may be called upon to fix any permissions that are not set this way, so as to allow the supervisor to access relevant research files and/or audit disk usage.

The subdirectories in imager/people are organized by userid, with each Imager lab member having the option of a private subdirectory. Files related to Imager research projects should never be placed here. Instead, this is extended as a courtesy to Imager lab members to supplement the quota on their personal home directory.

While there is generally no quota applied to the Imager filesystem in the interests of flexibility, the amount of disk space available is often almost completely utilized, and as research takes priority over personal use, excessive use of imager/people is monitored and dealt with by the following mechanism.

(1) If the imager-tech group finds, in the weekly disk usage report, that a directory in imager/people occupies more than 25GB, the owner of the directory and their faculty supervisor will be sent a warning email. This is a request to either clean up the space or to justify (with the explicit assent of the supervisor) why more space is necessary. (The 25GB limit may be revised up or down in the future, depending on circumstances.)

(2) If after two weeks the situation has not been resolved (space usage reduced or the OK from the supervisor), the imager-tech group will ask the tech staff to institute a hard quota for that user on the imager file system. This will make it impossible for them to use more space (in both /people and /project directories) until they have reduced their usage (in the user's /people directory) below the quota limit. The user and supervisor will simultaneously be informed of the quota by email.

(3) If after another two weeks the situation still has not been resolved, the imager-tech group reserves the right to delete all contents of the imager/people directory (for privacy reasons, no files will be examined, and thus it is impossible to selectively delete). At this point, the files may of course be retrieved from backed-up snapshots for a while longer, but not forever.

Hopefully none of these steps will need to be taken. Lab members are encouraged to put files in the appropriate place (imager/project vs. imager/people), clean up temporary files after use, use at least lossless compression for long-term storage of large media files, etc.