Comparing influx data with SNMP

[tuxis]

Hi,

we're working on something cool and are using the metric server service from Proxmox. While checking the values for IOPS, we see a different amount of IOPS in InfluxDB than we do via SNMP (in LibreNMS).

The influx iops reported by Qemu, are those the IOPS issues by the GuestOS to the VM, or are they the IOPS issued by KVM to the underlying storage? That might explain the difference were seeing.

 

[fabian]

those are the block stats as returned by qemu:

https://git.proxmox.com/?p=qemu-ser...468d329c8cfd6c4995c481008c54580;hb=HEAD#l2801
https://manpages.debian.org/buster/qemu-system-common/qemu-qmp-ref.7.en.html (query-blockstats / BlockDeviceStats)

 

[tuxis]

Hmm. So those are the iops issued to the device. Given the fact the we have something like iop-merging, it could be that SNMP actually counts before merging. Qemu obviously only sees the merged iops.

Thanks.