Back to main "Getting Started" document
File Systems, Quotas, and Data Handling
To see your current quota and your disk usage for your home directory, run this command:
quota -s
To see the quota and usage for the $PROJECTS directories for all groups that you belong to, run this command:
quota -s -g
The clustered file system $SHARED_SCRATCH provides fast, high-bandwidth I/O for running jobs. Though not limited by quotas, $SHARED_SCRATCH is intended for in-flight data being used as input and output for running jobs, and may be periodically cleaned through voluntary and involuntary means as use and abuse dictate.
For information on how to use $PROJECTS, please see CRC's Using the $PROJECTS File System.
Volatility of $SHARED_SCRATCH
The $SHARED_SCRATCH filesystem is designed for speed rather than data integrity and therefore may be subject to catastrophic data loss! It is designed for input and output files of running jobs, not persistent storage of data and software.
Don't move, but copy files to $SHARED_SCRATCH
When dealing with $SHARED_SCRATCH always copy your data in. A "cp" will update the access time on files whereas a move "mv" will preserve the access time. This is important as our periodic cleaning mechanism may purge files where the access time is maintained via the "mv" command.
Avoid I/O over NFS
$HOME and $PROJECTS should not be used for job I/O. Jobs found to be using $HOME and $PROJECTS for job I/O are subject to termination without notice.
Use Variables Everywhere!
The physical paths for the above file systems are subject to change. You should always access the filesystems using environment variables, especially in job scripts.
