Description of problem:

'used-bytes' value from 'virsh guestinfo' remains the same after downloading large file in fedora/rhel vm's
for Centos it works as expected, other OS do not work as expected

Version cnv-4.15:

How reproducible: 100% for fedora/rhel

Steps to Reproduce:
===============Centos Vm=============================

1) create a centos vm

2) connect to the virt-launcher pod of the centos vm by running following command:
oc rsh virt-launcher-centos-stream9-ruling-mammal-vvpwz

3) run command "virsh guestinfo 1 --filesystem" inside of virt-launcher pod
sh-5.1$ virsh guestinfo 1 --filesystem
Authorization not available. Check if polkit service is running or see debug message for more information.
fs.count : 1
fs.0.name : vda1
fs.0.mountpoint : /
fs.0.fstype : xfs
fs.0.total-bytes : 32144076800
fs.0.used-bytes : 2503639040
fs.0.disk.count : 1
fs.0.disk.0.alias : vda
fs.0.disk.0.device : /dev/vda1

4) download a large file from inside the vm:
(connect to the vm) virtctl console centos-stream9-ruling-mammal
wget http://mirror.ufs.ac.za/linuxmint/stable/14/linuxmint-14-kde-dvd-64bit.iso

5) run command "virsh guestinfo 1 --filesystem" inside of virt-launcher pod

sh-5.1$ virsh guestinfo 1 --filesystem
Authorization not available. Check if polkit service is running or see debug message for more information.
fs.count : 1
fs.0.name : vda1
fs.0.mountpoint : /
fs.0.fstype : xfs
fs.0.total-bytes : 32144076800
fs.0.used-bytes : 3599400960
fs.0.disk.count : 1
fs.0.disk.0.alias : vda
fs.0.disk.0.device : /dev/vda1

we can see both values increased for 'fs.0.used-bytes'

==========================Fedora VM ===================================

1) create fedora/rhel vm
2) connect to the virt-launcher pod of the fedora/rhel vm:
oc rsh virt-launcher-vm-fedora-cpu-mem-1-wzbrx

3) run command "virsh guestinfo 1 --filesystem" inside of virt-launcher pod:
virsh guestinfo 1 --filesystem
Authorization not available. Check if polkit service is running or see debug message for more information.
fs.count : 2
fs.0.name : vda2
fs.0.mountpoint : /boot
fs.0.fstype : ext4
fs.0.total-bytes : 943562752
fs.0.used-bytes : 117858304
fs.0.disk.count : 1
fs.0.disk.0.alias : vda
fs.0.disk.0.device : /dev/vda2
fs.1.name : vda3
fs.1.mountpoint : /boot/efi
fs.1.fstype : vfat
fs.1.total-bytes : 104607744
fs.1.used-bytes : 12107776
fs.1.disk.count : 1
fs.1.disk.0.alias : vda
fs.1.disk.0.device : /dev/vda3

4) download a large file inside the vm
(connect to the vm) virtctl console vm-fedora-cpu-mem-1:
wget http://mirror.ufs.ac.za/linuxmint/stable/14/linuxmint-14-kde-dvd-64bit.iso

5) run command "virsh guestinfo 1 --filesystem" inside of virt-launcher pod
sh-5.1$ virsh guestinfo 1 --filesystem
Authorization not available. Check if polkit service is running or see debug message for more information.
fs.count : 2
fs.0.name : vda2
fs.0.mountpoint : /boot
fs.0.fstype : ext4
fs.0.total-bytes : 943562752
fs.0.used-bytes : 117858304
fs.0.disk.count : 1
fs.0.disk.0.alias : vda
fs.0.disk.0.device : /dev/vda2
fs.1.name : vda3
fs.1.mountpoint : /boot/efi
fs.1.fstype : vfat
fs.1.total-bytes : 104607744
fs.1.used-bytes : 12107776
fs.1.disk.count : 1
fs.1.disk.0.alias : vda
fs.1.disk.0.device : /dev/vda3

fs.0.used-bytes values remain the same after downloading large file
================================================================

Actual results:
fs.0.used-bytes remains the same value after downloading a large file in fedora vm

Expected results:

fs.0.used-bytes value should be increased for fedora/rhel by executing "virsh guestinfo 1 --filesystem > after downloading a large file

Additional info:
the issue is not reproducible in Centos VM