Summary of Default File Quotas
Quota limits are necessary to ensure that disk space can be made available to all users and that work is not impeded by full file systems. The /g home directories are on both the OCF and SCF machines. The default quota is 16 GB.
The /g/g* (global) home file systems are provided on Network Appliance NFS servers. If you are using over 90% of your allotted space, a warning will be displayed upon login. Please don't miss this login announcement.
To see your current usage and quota limits, type
(where -v signifies verbose).
The /nfs/tmp* scratch file systems are provided on Panasas and BlueArc NFS file servers. The default user quota in an /nfs/tmp* directory is 2 TB. The size of an individual directory can be determined by using bdf. Due to security concerns, some platforms do not mount the global home nor the /nfs/tmp* file systems. While these platforms are dealt with on a case-by-case basis, every effort is made to have 16 GB quotas for home directories.
Note: Keep in mind the purge run on /nfs/tmp* spaces (see the file purge policies). This may cause loss of data even if you are not close to your quota limit. The /p/g* and /p/l* file systems have no quota but may also be subject to purge. Because of architectural limitations, these file systems are not cross-mounted as are the /nfs/tmp* and global home directories.
Requests for additional disk space for /nfs/tmp* and the home directories should be directed to the LC Hotline through your Computer Coordinator or PI. The request must include justification for the larger need.
PLEASE ATTEND TO WARNING MESSAGES!
You risk losing data if you exceed your quota. Output to a home directory that is over quota will be truncated. Files moved to such a directory will also be truncated. Just opening a file for editing while you are over quota can cause the loss of the entire file's contents. Unfortunately, these are results of the UNIX implementation of quota and can be prevented only by user attention to quota warnings.
Carefully consider before you execute a batch job that attempts to write to your home directory space. If you exceed disk space quota:
- You will get truncated or zero length files and waste the run because the output is lost as a result.
- You will lose further data if your home directory remains filled after the job finishes, if you attempt to copy, write or edit files.
- MULTIPLE ATTEMPTS TO WRITE TO A DIRECTORY THAT IS OVER QUOTA WILL CREATE A SIGNIFICANT BURDEN ON THE NFS SERVER, CAUSING INTERACTIVE DELAY AND PERFORMANCE PROBLEMS. In some cases, jobs create hundreds of thousands of write attempts, quota checks, and refusals to write within a few minutes.