RLS access does not change the format of the data in the VSAM data sets. The data sets are compatible for non-RLS access. If the data set has been defined with a cross-region share option of 2, a non-RLS open for input is permitted while the data set is open for RLS processing; but a non-RLS open for output fails. If the data set is already open for non-RLS output, an open for RLS fails. Therefore, at any time, a data set can be open for non-RLS write access or open for RLS access.To open a data set specifying RLS-in-use for non-RLS access, SMSVSAM must be active on the system issuing the non-RLS open.

CICS and VSAM RLS provide a quiesce function to assist in the process of switching a data set from CICS RLS usage to non-RLS usage.