If your  /sapmnt/<SID>/global directory is full it wil result in failing of BG jobs. Becuase it stores logs for various BG processes. 
You need to check this in your daily checks.
Tx : se38
Report RSBTCDEL2

Schedule a job  using above Tcode to delete Workflow logs WF_LOGS*
Tx:  SWU10 or SWT0 
Report: RSWTTR02