bug#14963: The values for the same file-system differ depending on the file tested

[Zahariev, Boris]

 ~]$ sudo df -h /nfs/eq-fas3240-001a/vol/a0content1/rcuvb/
Filesystem            Size  Used Avail Use% Mounted on
eq-fas3240-001a:/vol/a0content1
                      549G  501M  549G   1% /nfs/eq-fas3240-001a/vol/a0content1

 ~]$ sudo df -h /nfs/eq-fas3240-001a/vol/a0content1/rcuniverse/
Filesystem            Size  Used Avail Use% Mounted on
eq-fas3240-001a:/vol/a0content1
                      380G  495M  380G   1% /nfs/eq-fas3240-001a/vol/a0content1


The values for the same file-system differ depending on the file tested?