[libvirt-users] libvirt blkiotune mechanism

[Maksym Isaiev]

Hello!

We are using oVirt in our infrastructure, which uses libvirt as backend. Last time we needed to activate storage QoS aka  libvirt blkiotune parameters. So some questions appeared about how libvirt limitation mechanism works:

1. What happened to overlimit storage traffic in small time period after we apply blkiotune parameters on high loaded virtual machine on fly:
a) All over-limit traffic pulled into some queue, where all disk transactions can be successfully finished with QoS throughput?
b) All over-limitation data dropped and opened transactions state became failed?
c) All active transactions finishes on speed beyond blkiotune parameters limit, but all new transactions immediately are limited based on configured limits?


Thanks in advance!