Filesystem Quotas and Purging

Overview

file system space inodes purge time
Project 1 TB 1 M -
Global HOME 40 GB 1 M -
Global common 10 GB 1 M -
Cori SCRATCH 20 TB 10 M 12 weeks

Policy

NERSC data management policy.

Quotas

Warning

When a quota is reached writes to that filesystem may fail.

Note

If your $SCRATCH usage exceeds your quota, you will not be able to submit batch jobs until you reduce your usage.

Current usage

NERSC provides a myquota command which displays applicable quotas and current usage.

To see current usage for home and available scratch filesystems:

nersc$ myquota

For project you can use

nersc$ prjquota <project_name>

or use myquota with the full path to the directory

nersc$ myquota --path=/project/projectdirs/<project_name>

For global common software you can use

nersc$ cmnquota <project_name>

or use myquota with the full path to the directory

nersc$ myquota --path=/global/common/software/<project_name>

Increases

If you or your project needs additional space you may request it via the Disk Quota Increase Form.

Purging

Some NERSC file systems are purged. This means the files not read (i.e. atime is updated) within a certain time period are automatically deleted. You can see the time period for the purged file systems at NERSC in the overview table. When a purge is done, a file named .purged_<date\> is left behind. This is a text file that holds the names of the files that have been removed. These .purged files will not be deleted by our purges to make sure a record of purging activities is retained. Touching files or other activites intended to circumvent the purge are forbidden by NERSC policy.