large data capturing and filter by Vlans

edit

hii to all

i trying to capture larfe files to resolve some problem that Occurs in fairly large hours, so I have to leave the wireshark capturing open...

i filtering by "arp and icmp"

but the files too large.. i trying to filter by vlan and this filtring desnt work--> "vlan 200"

have some ideas ?

and maybe some tips to incrase the wireshark power? i using computer : i7 intel 64 bit 64 Ram tanks!