how to increase /root xfs filesytem on exadata KVM GUEST

Hello,

can we please extend the root filesystem by

A/increasing the size of the disk image system.img (in my case File /EXAVMIMAGES/GuestImages/coe01prodc02.zit.commerzbank.com/System.img

)

or

B/ is it a must to increase it by using the plan stated in oracle documentation eg,increase the size of the volume group VGExaDb and extend the logical volumes /dev/VGExaDb/LVDbSys1       and /dev/VGExaDb/LVDbSys2?

for A/we plan to use the follwing steps:

on KVM Host

cd /EXAVMIMAGES/GuestImages/<domain_name>

vm_maker --stop-domain <domain_name>

qemu-img resize System.img +45G

on KVM Guest