Explicitly setting sparse=true makes "--force" takes effect.
====
$ virt-install --noautoconsole --name test --ram 512 --boot hd --disk pool=default,size=2048,format=qcow2,sparse=true
WARNING The requested volume capacity will exceed the available pool space when the volume is fully allocated. (2097152 M requested capacity > 41166 M available)
ERROR The requested volume capacity will exceed the available pool space when the volume is fully allocated. (2097152 M requested capacity > 41166 M available) (Use --force to override)
$ virt-install --noautoconsole --name test --ram 512 --boot hd --disk pool=default,size=2048,format=qcow2,sparse=true --force
WARNING The requested volume capacity will exceed the available pool space when the volume is fully allocated. (2097152 M requested capacity > 41166 M available)
Starting install...
Allocating 'test.qcow2' | 2.0 TB 00:07
Creating domain... | 0 B 00:00
Domain creation completed. You can restart your domain by running:
virsh --connect qemu:///system start test
Explicitly setting sparse=true makes "--force" takes effect.
====
$ virt-install --noautoconsole --name test --ram 512 --boot hd --disk pool=default, size=2048, format= qcow2,sparse= true
WARNING The requested volume capacity will exceed the available pool space when the volume is fully allocated. (2097152 M requested capacity > 41166 M available)
ERROR The requested volume capacity will exceed the available pool space when the volume is fully allocated. (2097152 M requested capacity > 41166 M available) (Use --force to override)
$ virt-install --noautoconsole --name test --ram 512 --boot hd --disk pool=default, size=2048, format= qcow2,sparse= true --force
WARNING The requested volume capacity will exceed the available pool space when the volume is fully allocated. (2097152 M requested capacity > 41166 M available)
Starting install...
Allocating 'test.qcow2' | 2.0 TB 00:07
Creating domain... | 0 B 00:00
Domain creation completed. You can restart your domain by running:
virsh --connect qemu:///system start test