hello , i did a kvm guest with virt-manager and installed windows server 2016. performance settings for the disk: hypervisor default for cache & io mode i added a 2nd disk to the guest , also with hypervisor default settings on cache & io mode Under disk settings in windows server 2016 i set "format whole disk NTFS" i did not choose the "quick format" option. when windows is formatting this 1TB drive the performance on the virtualisation host goes down loging via ssh take ages, top take 2 mins to start up. the physical disks are connected to a raid controller LSI and FS on virtualisation server where the qcow2 files are is XFS. DO i have to set another options for "performance options" as "hypervisor default" to keep the system performant on formatting the disk? thanks for any hints. marko -- zbfmail - Mittendrin statt nur Datei!