DPM 2012 SP1 Backup SQL DB failed with

Hello,

I'm using DPM 2012 backup SQL 2008 R2 databases that recently found some instances backup failed with "DPM doesn't have sufficient storage space available on the recovery point volume to create new points (ID 214)

With my research for the error, it is caused by disk space on  recovery point volume is lower, but currently we expanded 100GB again, but the backup job still failed with same error and new expanded 100GB is not used. Note: we have enable "Automatically grow the volumes"

Thanks.

Steve Xu