fletcher4 checksum - where is it used with zvols?

[imtiazdc]

Hi,

Can someone please comment if/where is fletcher4 used (in the kernel, not userland) in current form of OpenZFS when dealing with volumes (not filesystem)?

What are the properties I need to create the zpool and zvol with so that I can hit the below function in the debugger attached to the kernel?

zfs/module/zfs/zio_checksum.c

Line 132 in 5b52516

abd_fletcher_4_native(abd_t *abd, uint64_t size,

Thanks,
Imtiaz