Volume 5, Number 2
June 2006

My MCSR Disk Usage

A new feature, My Disk Usage, has been added to the My MCSR web portal on the MCSR Web Pages. As with the other individualized views on the My MCSR portal, you will first need to login to My MCSR with your email address (or research account name) and password, which can be emailed to you if you've forgotten them. If you only want to have to ever login once from that computer, choose "Remember me at this computer" before submitting your password. Once logged in, click My...Disk Usage. Your Hourly and Daily /tmp and /ptmp usage amounts are listed for all of your MCSR accounts on all systems. Use this tool to track how your disk usage increases over time as jobs run and exit on the supercomputers. Note also that System Disk Usage can be viewed on a global level as well, to see which disk subsystems are getting full.

As a reminder, MCSR policy provides 20 GB of /ptmp quota per account on sweetgum and redwood. There are no individual quotas on /tmp (sweetgum and redwood) or /ptmp (mimosa), since individual use of these areas for scratch files can vary widely based on a user's current job mix. However, /tmp file systems, and /workX ptmp partitions, can and will fill up if enough users create large enough scratch files in a short period of time. MCSR watchdog scripts look for and notify staff and users of file systems that exceed preset thresholds and are in danger of filling up. If you receive such a message, you might access the My Disk Usage web page to see whether your disk usage is growing at an alarming pace, and if necessary, kill one or more jobs, or delete large files. Although we will attempt to notify you if your jobs or leftover scratch or output files are combining with those of other users to endanger a file system, we reserve the right to delete any user jobs or remove user scratch files on disks that are in imminent danger of filling up, since a full disk system will lead to the termination of all jobs of users of that disk system as those jobs attempt to, and are unable to, append to their output or scratch files.

As an additional reminder, jobs that you anticipate will use over 50GB of scratch space should be submitted on mimosa using the -d option to g03sub. By specifying a needed amount of disk space over 50GB with the -d option, you will ensure that your scratch files will be written in a larger disk subsystem that is much less likely of filling up. For shared memory jobs requiring excessive disk space, we recommend redwood, since it has a much larger /tmp system than does sweetgum.