For non-RLS access, VSAM uses the share options settings to determine the type of sharing allowed. VSAM provides full read and write integrity for the VSAM RLS users, but does not provide read integrity for the non-RLS user. You cannot specify a non-RLS open-for-output request when the data set is already opened for VSAM RLS.

VSAM RLS provides read sharing and write sharing for multiple users; it does not use share option settings to determine levels of sharing. When you request an RLS open and the data set is already open for non-RLS input, VSAM does check the cross-region setting. If the share option is 2, the data set can be opened in RLS mode. The open fails if you use any other share option, or if the data set is opened for non-RLS output.