I'm not sure which qemu disk drivers/busses support this, but at least virtio does so. I'm using it for development.

On 06/10/2015 03:24 PM, Fabian Deutsch wrote: > ----- Original Message ----- >> oVirt Node - 3.5 - 0.999.201504280931.el7.centos >> >> Using our shared storage via baremetal (stock CentOS 7) -> iscsi, I can >> successfully issue fstrim commands. With oVirt at the VM level, even >> with direct LUNS, trim commands are not supported despite having the LVM >> config in the VMs set up to allow it. > Hey, > > IIUIC you try to get discard working for VMs? That means that if > fstrim is > used inside the VM, that it is getting passed down? > > The command line needed for qemu to support discards is: > > $ qemu … -drive if=virtio,cache=unsafe,discard,file=<disk> … > > I'm not sure which qemu disk drivers/busses support this, but at least > virtio does so. > I'm using it for development. > > You could try a vdsm hook to modify the qemu command which is called > when the VM is spawned. > > Let me know if you can come up with a hook to realize this! There's this hook in code review intended to do so: https://gerrit.ovirt.org/#/c/29770/ > > Greetings > fabian > _______________________________________________ > Users mailing list > Users(a)ovirt.org > http://lists.ovirt.org/mailman/listinfo/users _______________________________________________ Users mailing list Users(a)ovirt.org http://lists.ovirt.org/mailman/listinfo/users