Hi All, I am trying to collect memory, disk and network stats for a VM on kvm host. It seems that the statistics are not matching what the OS inside the VM is reporting. Why is this discrepancy ? Is this a known bug of libvirt ? Also I heard that libvirt shows cumulative figures for these measures ever since the VM was created.  Also I tested by creating a new vm and comparing the stats without a reboot . Even in this case, the stats dont agree.  Can someone help me here please ? Thanks Kumar

Thanks Marco for the response. Is it possible to collect these vm stats from the host KVM hypervisor ? Also can u give the link for this book ? Thanks Happy holidays On Monday, December 26, 2022, Marko Horn <weber(a)zbfmail.de&gt; wrote: > Hi, > > I think best way is to use BPF to collect stats. I did this in past in combination with 'perf'. > Theres a nice book of Brandon Greg from Netflix Networks where he describe how to do this and how to write own scripts. > > merry Xmas > > marko > > ________________________________ > > 26.12.2022 11:34:20 Gk Gk <ygk.kmr(a)gmail.com&gt;: > > Hi All, > I am trying to collect memory, disk and network stats for a VM on kvm host. It seems that the statistics are not matching what the OS inside the VM is reporting. Why is this discrepancy ? > Is this a known bug of libvirt ? Also I heard that libvirt shows cumulative figures for these measures ever since the VM was created.  Also I tested by creating a new vm and comparing the stats without a reboot . Even in this case, the stats dont agree.  Can someone help me here please ? > > Thanks > Kumar >

So, can I derive cpu, memory, disk and network stats of the VMs ? On Monday, December 26, 2022, Marko Horn <weber(a)zbfmail.de&gt; wrote: > Hello, > > yes I can :-) > > https://www.brendangregg.com/ > > on the page you will find a link to his 'Linux Performance' book. > On the page are also further Infos about the topic 'performance'. > you will have to dive into the stuff. > (e)BPF is a "MIGHTY" area. > But you can pull out nearly 'every' meta data from the kernel. > > Also for your interest: > > https://www.brendangregg.com/Slides/SREcon2022_ComputingPerformance/ > > Computing Performance 2022 and what is on the horizon! > > have fun! > > Slainte > > ________________________________ > > 26.12.2022 18:09:39 Gk Gk <ygk.kmr(a)gmail.com&gt;: > > Thanks Marco for the response. Is it possible to collect these vm stats from the host KVM hypervisor ? Also can u give the link for this book ? > > Thanks > Happy holidays > > On Monday, December 26, 2022, Marko Horn <weber(a)zbfmail.de&gt; wrote: >> Hi, >> >> I think best way is to use BPF to collect stats. I did this in past in combination with 'perf'. >> Theres a nice book of Brandon Greg from Netflix Networks where he describe how to do this and how to write own scripts. >> >> merry Xmas >> >> marko >> >> ________________________________ >> >> 26.12.2022 11:34:20 Gk Gk <ygk.kmr(a)gmail.com&gt;: >> >> Hi All, >> I am trying to collect memory, disk and network stats for a VM on kvm host. It seems that the statistics are not matching what the OS inside the VM is reporting. Why is this discrepancy ? >> Is this a known bug of libvirt ? Also I heard that libvirt shows cumulative figures for these measures ever since the VM was created.  Also I tested by creating a new vm and comparing the stats without a reboot . Even in this case, the stats dont agree.  Can someone help me here please ? >> >> Thanks >> Kumar >>