Technical Bulletin #492: Lustre Parallel File System Purge Policy Update [Deprecated]
DEPRECATED—This purge policy is superseded by TB#523.
The purge policy outlined herein supersedes the purge policy in Technical Bulletin Nos. 351 and 411. This updated purge policy will go into effect on all of the /p/lscratch* Lustre file systems on the Open and Secure Computing Facilities (OCF and SCF) beginning April 15, 2014.
Livermore Computing (LC) recognizes that our users' work can be seriously impacted when a file system fills to capacity or near capacity, and users may experience degraded performance and/or receive I/O errors when writing to the file system. To minimize the potential disruption of service, a Lustre parallel file system purge policy was implemented in August 2006 and is updated in this Technical Bulletin.
- Purging of files will take place on an on-going, as-needed basis. Purges are typically triggered when a file system reaches 80% of capacity.
- When a purge is needed, all files that have not been accessed for 60 days are eligible to be deleted.
- Intentional subversion of the purge policies of any temporary LC file system (e.g., the use of the UNIX command touch) is strictly forbidden. Users observed intentionally subverting these policies will have their responsible manager contacted and may have their computing privileges suspended until assurances are provided to LC by the user and their responsible manager that the behavior will not continue.
Once files are purged, there is no possibility of recovering them. Lustre file systems are scratch file systems and are not backed up, so any critical files should always be backed up to another medium, such as archival storage.