And I'd call both of those scenarios "not applicable" because iscsi extents should not be file-based extents. zvols are their own file system (similar to a dataset) and I will call you silly if you make a dataset for each zvol to be stored in.
What would you do in this situation?
Yesterday I tried to mount a zvol device in my VMWare, but it doesn't work.
I created a zvol with the "Sparse volume" checked, I changed the block size to 64K, created a new portal, initiator, target, extent, everything normal. But when I setup the new informations on VMWare (same iSCSI IP but different ports), a rescan is requested automatically, but the LUN does not appear.
There are many messages like this in the VMware event log:
Login to iSCSI target iqn.2014-12.br.com.enterprise.esxi:vmware18tb on vmhba37 @ vmk2 failed.
The iSCSI initiator could not establish a network connection to the target.
error
12/06/2015 12:09:50
vmserver.enterprise.com.br
Login to iSCSI target iqn.2014-12.br.com.enterprise.esxi:vmware18tb on vmhba37 @ vmk3 failed.
The iSCSI initiator could not establish a network connection to the target.
error
12/06/2015 12:09:50
vmserver.enterprise.com.br
iSCSI discovery to 192.168.6.2 on vmhba37 failed
. The iSCSI Initiator could not establish a network connection to the discovery address.
error
12/06/2015 12:09:50
vmserver.enterprise.com.br
iSCSI discovery to 192.168.5.2 on vmhba37 failed
. The iSCSI Initiator could not establish a network connection to the discovery address.
error
12/06/2015 12:09:40
vmserver.enterprise.com.br
vmware18tb is the extent FILE, it is working fine, without any problem.
nowhere nothing about the new zvol is mentioned.