What does this Mean?

It's really frustrating to have a job run for a long time - it was at 47:23:17 when I took the screenshot below - and to realize you cannot let the job finish. There was 150 GB more to be synched up to the "easystore" drive but... there is only 54.4 GB free on that drive. After I eliminate 95.6 GB on the "easystore" drive, I will finish.