My 7 yr old is sleepwalking and he is crying rubbing his tummy and vomits then peacefully goes to sleep and has no memory of it in morn. 2 mts now?

Weird Sleep behavior. Sleep related behaviors are fairly common in children. Some children may arise and engage in complex and unexpected behaviors without any recollection(including our son's infamous "sleep peeing") these behaviors are more common in school age kids and may follow sleep disturbances. But, if your child is vomiting nightly for 2 months, that is unusual and i would seek further consultation.
Sleep entry disorder. Sleep walking/night terrors are oddities in childhood that may reflect a more rapid entry into deep sleep, possibly triggered by unrecognised sleep deficit.The barfing is worrisome, but pattern behavior is common. If the kid checks out at the dr, he might benefit from a scheduled power nap (30-40min) prior to supper.Over time the sleep deficit should fade &events should deminish.