A customer had problems synchronizing large amount of data to an EMC CIFS share using the robocopy /mir commandline option.

2011/07/14 13:38:58 ERROR 112 (0x00000070) Creating Destination Directory \\xxxx\xxx\
There is not enough space on the disk.

Waiting 30 seconds...

After some troubleshooting I found that opslock, hidden sharing and CIFS caching were not the problem but the fact that the share was thin created. I created 2 shares, one thin and one fat. You guessed it right, the thin version failed. Changed the properties to fat and the problem was gone!