How to force group ownership on samba share?

I have a samba server running on ubuntu server 12.04. Only one folder /sharetest is shared with group storageusers, and users user1, user2, wowza are members of it. Here is smb.conf

#======================= Global Settings =====================================
[global]
workgroup = WORKGROUP
server string = Samba Server %v
netbios name = ubuntu
security = user
map to guest = bad user
dns proxy = no
#============================ Share Definitions ==============================
[Storage]
path            = /sharetest
browsable       = yes
writeable       = yes
guest ok        = no
valid users     = @storageusers
create mask     = 0775
directory mask  = 0775

A second ubuntu server 12.04 will be using above mentioned share. The share on the second server is automounted via fstab line

//192.168.1.12/Storage /share smbfs credentials=/root/.smbcredentials,gid=0 0 0

File and folders created inside share folder on the second server have ownership of user wowza and group wowza. I assume because of this other share users do not have access to writing or deleting files and folders. Is there a setting for samba server that will force all files and folders created on share to have group ownership set to storageusers instead of user's primary group?

Solution 1:

I was able to find the answer about ten minutes after posting this. Source: http://www.linuxquestions.org/questions/linux-server-73/ownership-on-new-files-in-group-samba-share-set-badly-898489/

chgrp storageusers /sharetest && chmod g+s /sharetest