Need help

Hi All, I am trying to get guest VM's disk statistics using a libvirt python library as follows: --- raw_xml = domain.XMLDesc(0) for disk in doc.getElementsByTagName('disk'): disk_data = disk.getElementsByTagName('target') --- The above code is yielding the following stats for two disks inside the VM: -- disk_name=sda read_req=34137,read_bytes=445358592,write_req=2405970,write_bytes=24943391744 disk_name=sdb read_req=34357,read_bytes=450754048,write_req=2405984,write_bytes=24943465472 --- The write_bytes divided by 1024 yields 24358853 kB. But when I compare the above statistics from the iostat data shown from inside the VM, I see a stark difference between the two results as shown below: --- root@sample:~# iostat Linux 4.15.0-101-generic (sample) 12/21/2022 _x86_64_ (1 CPU) avg-cpu: %user %nice %system %iowait %steal %idle 0.27 0.00 0.03 0.02 0.01 99.68 Device tps kB_read/s kB_wrtn/s kB_read kB_wrtn sda 0.24 0.04 11.87 400052 121844120 sdb 0.00 0.00 1.19 5269 12223752 ---- Why is there a huge difference in the number of bytes read and written for the two disks as reported by libvirt ? Please explain. Thanks Kumar