HDFS capacity

[#1]

There is an issue when I upload files into HDFS. Our application get a error message about the files were uploaded had exceed the quota of HDFS. I checked the quota of user of HDFS. But remaining storage space than more space of the files needed.
And I cleared the quota of user of HDFS. The upload is completed. And then I checked the space of HDFS used. The operation did not take lots of space of HDFS.

The issue has several times in our system.
I want to know what the reason is.

[#2]

Can you please post the error received and directory usage along with the quota configured for the user? 

[#3]

@qiang Have you resolved your issue and if so would you mind sharing the solution and marking this thread as solved? If you are still experiencing the issue, can you provide the information @amk has requested?