Hi Roberto, What is the cpu and memory configuration of your guest? Are you pinning to dedicated CPUs, are you exposing host topology and cpu features, do you have dedicated I/O threads? Are you backing the guest memory with hugepages? All of the above will likely increase performance and minimise noise.
Cheers, On 6 December 2016 at 05:13, Roberto Fichera <ker...@tekno-soft.it> wrote: > Hi There, > > I've moved some Windows2012 with MSSQL VMs from an hold ESXi 5.5 machine > to a more recent and powerful machine running Fedora 24 x86_64 and related > libvirt + KVM > virtualization. I've moved the VMs filesystem to LVM slices and installed the > VirtIO drivers > in to all Windows VMs. I've also set both Disk and Network interface to work > using VirtIO. > So far so good everything works pretty fine. Now I would like to tune at best > the MSSQL VM > for both Disk and Network interfaces in order to get the best performance > possible. > > Regarding network interface I've set it to work as bridge instead to go > through to macvtap, so I'm > not sure what is the best in this case. > > Regarding disk, since it's LVM I've chosen to go to cache mode none and IO > mode native. Also > here cannot judge what's the best setup for the workload. I'm undecided to > use IO mode threads > along directsync cache mode. > > Finally I've set "ionice -c 1 -p <qemu-pid> -n 0" and "renice -n -10 > <qemu-pid>" for the interested > VM that I want to get best performance possible. > > Even with the above setup, the MSSQL VM has performance similar to the old > machine running > ESXi 5.5, so does anyone can suggest where too look at and/or what would be > the right setup? > > Thanks in advance. > Roberto Fichera > > > _______________________________________________ > libvirt-users mailing list > libvirt-users@redhat.com > https://www.redhat.com/mailman/listinfo/libvirt-users -- Cheers, ~Blairo _______________________________________________ libvirt-users mailing list libvirt-users@redhat.com https://www.redhat.com/mailman/listinfo/libvirt-users
