>>>>> "Lukas" == Lukas Czerner <lczerner@redhat.com> writes: Lukas, Lukas> [root@trim ~]# lvcreate -L 3500M vg_test Lukas> Logical volume "lvol0" created Ok, so here's what I think is going on. You're creating a linear target which happens to fit inside the first PV. Here's two devices. One that supports discard_zeroes_data=1 (8:17) and one that doesn't (8:49). # dmsetup table foo-bar: 0 1032192 striped 2 32 8:17 384 8:49 384 foo-baz: 0 106496 linear 8:17 516480 # grep . /sys/block/d*/queue/discard_z* /sys/block/dm-0/queue/discard_zeroes_data:0 /sys/block/dm-1/queue/discard_zeroes_data:1 LV foo/bar (dm-0) is striped, straddling two devices with incompatible values. Hence 0. LV foo/baz (dm-1) is linear and fits inside the first PV. Thus it has discard_zeroes_data=1. -- Martin K. Petersen Oracle Linux Engineering _______________________________________________ linux-lvm mailing list linux-lvm@redhat.com https://www.redhat.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
