[Libguestfs] Need Help

Hello Experts, I need a help from you . I am using CentOS 6.4 and using guestfish to modify an ESX image. I am adding a disk, executing "run" command and mounting it. the "run" command is taking around 50 seconds . Is there any way to minimize it. If we can not minimize it then Can we create and keep the guestfish virtual shell open so that we can just add a disk , mount and modify the image in few seconds. Need your expert advice. Many Thanks in advance. Thanks & Best Regards, Priyanka.