What is _pre folder?

The _pre folder is used as a temporary storage for files whose checksum has yet to be calculated. So

before moving them to their correct location, we save them within _pre folder, calculate their checksum and finally move them to their correct destination.

If a move is not possible, or if we encounter a checksum error, the file is deleted. So if Artifactory is either shutdown, or if the process fails (OOME, Disk Full, etc..), the file may be orphaned.

While Artifactory is shut-down(turned off), you can safely delete any files from the _pre folder. Otherwise, you may search for any files that have been in the _pre folder for an extended period of time. For example, you may run the following to clean the _pre folder for any files that are older than 2 days. 

 

find  <$CLUSTER_HOME>/ha-data/filestore/_pre/* -mtime +2 -exec rm {} ;