<driver name='qemu' type='raw' cache='none' io='native'/> This opens the underlying device (lvm) via O_DIRECT and submits Linux AIO requests to the device. If the VMs are sharing the LVM pool it may be overwhelming the underlying devices.
This feels like there are syncs after each write which is going to serialize access to the LVM (and underlying devices). IDE emulation allows only one outstanding IO request; that likely keeps things fair. Can you share how the LVM is configured (pvs, vgs, lvs)? Can you attach capture some iostat data in your idle and busy cases: iostat -x -k 2 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1666555 Title: update-grub slow with raw LVM source dev + VirtIO bus To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/qemu/+bug/1666555/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
