如何启用从KVM guest虚拟机到ZFS zvol iSCSI目标的空间回收?

我有一个ZFS卷“tank / kvm / webhosting”,通过iSCSI(使用tgt )暴露给KVM guest。

 <disk type='block' device='disk'> <driver name='qemu' type='raw' cache='none' io='native' discard='unmap'/> <source dev='/dev/disk/by-path/ip-10.1.200.2:3260-iscsi-iqn.2016-05.bla:webhosting-lun-1'/> <target dev='sda' bus='scsi'/> <address type='drive' controller='0' bus='0' target='0' unit='0'/> </disk> 

如何在ZFS上启用空间回收? 来自客人端的工作( fstrim -v / ),但iSCSI / ZFS主机在日志中显示错误:

 tgtd[324]: tgtd: bs_rdwr_request(227) Failed to punch hole for WRITE_SAME command tgtd[324]: tgtd: bs_rdwr_request(370) io error 0x18086b0 93 -1 0 2674021892096, No such device 

属性Thin-provisioning: Yes在LUN上设置为是。