The file system /scratch on Setonix is a Lustre filesystem that makes automatic use of file striping to increase I/O performance. This means that files are automatically divided into chunks that are written or read simultaneously across a set of Object Storage Targets (OSTs). In previous systems, it was recommended to manually set optimal file striping parameters depending on the size of the different files read/written by applications but, in current Lustre systems, this is not longer needed, thanks to the Progressive File Layout (PFL) technology.

PFL automatically enforces different striping settings for different segments of the files as they grow, allowing great I/O performance for most of the applications without the need for users to "optimise" their own striping settings. Because of this, we ask users not to manually adjust the file striping. If users feel the default PFL settings are not meeting their needs, please contact raise a ticket to the helpdesk.

Related pages

• Helpdesk Service
• Pawsey Filesystems and their Use
• Filesystem Policies