When a thin-pool is activated we see logs like "kernel: device-mapper: thin: Data device (dm-N) max discard sectors smaller than a block: Disabling discard passdown."

Issue

1. Create a VDO volume with the default settings, and an optional logical size (in our case, we used 300 GB)

vdo create --name=vdo1 --device=/dev/sdb --vdoLogicalSize=300G

2. Create a thin-pool on top of the VDO volume:

pvcreate /dev/mapper/vdo1
vgcreate TEST /dev/mapper/vdo1
lvcreate -L 200G -T TEST/dmthin1

When the thin-pool is activated, it will print a kernel log message saying that discard passdown was disabled because the max discard sectors of the VDO volume is smaller than "a block"

(output from lvcreate command)

  Thin pool volume with chunk size 128.00 KiB can address at most 31.62 TiB of data.
  Logical volume "dmthin1" created.

(/var/log/messages shows the following logs)

Jul 11 09:40:39 localhost kernel: device-mapper: thin: Data device (dm-5) max discard sectors smaller than a block: Disabling discard passdown.
Jul 11 09:40:39 localhost lvm[11450]: Monitoring thin pool TEST-dmthin1.