CentOS - Jan 2011 - xfs_quota - space differs between du -h vs report -h

Hi all,

I'm having fun getting to know xfs_quotas.

I do notice some irregularities.

When running xfs_quota -s -c /dev/sdc1

And then running report -h, for user barney, his used space is 4.9G  
while his soft/hard limit is 5G.

Since I set 5, all is well, but when I run du -hs on barnies dir, it  
shows only 4G used.

I can adjust for the diff so that my quotas can be set to 6G when I  
really mean 5G, that is if its a linear diff vs a algo diff.

However I was hoping you all could shed some light on this.

- aurf