Other File Systems

User Home Directories

Your home directory is located at /home/login-name.  Home directories are cross-mounted to all PDSF nodes, are regularly backed up, and currently have 5 GB disk quotas. The "myquota" command shows quotas and usage in terms of space (GB) and inodes.  Use the -M option of myquota to display in MB instead of GB.  See also Checking quotas for more about myquota.

Home directories are backed up as insurance against catastrophic file system failure.  Individual files or directories can not be restored so users must back up important files to HPSS, to local storage, or elsewhere.  Please back up all your important files on a regular basis.

Local Scratch Directories

These areas are designated as /scratch on each PDSF node.  The disks are not cross mounted between nodes in the PDSF system.

The scratch areas currently are partitions (~10 GB for batch nodes and 658 GB for interactive nodes) useful for single node processes with significant I/O requirments which can be directed to locally stored data files.  Files in these areas are not backed up and should be moved to more stable storage areas after use.

We have the following policy for scratch cleanup on the interactive nodes:

• If the partition is greater than 95% full, delete all files except those of running jobs.

On batch nodes only files belonging to the currently running jobs are kept.  Users can request their batch jobs to be sent to nodes with a specific amount of scratch space available by specifying a scratch resource requirement.

Use of /common

The /common file system is a special file system primarily for software installations.  It is optimized for reading of files and should be treated as a read-only file system as much as possible.  It is NOT to be used for general purposes such as writing log files, batch job output files, etc.

NGF (/project)

While technically not part of PDSF the NERSC Global File System (NGF) is available from all PDSF nodes as /project.  You can write under your group's directory which is located at /project/projectdir/<groupname>.  If your group does not have such a directory you should use the request form to get one created.  Note that prjquota is used instead of myquota on NGF - see Checking quotas for more information.  See also the NERSC webpages about Science gateways.

Note that you can host webpages on NGF.  See Hosting Webpages for more information.