Text and binary file size are saved on non-volatile storage (DASD) for quick access and maintained by the server for these data set types:

• Physical sequential (including striped)
• VSAM ESDS
• VSAM KSDS
• VSAM RRDS
• PDSE members

These data sets must be SMS managed. When the NFS accesses a data set for the first time, it performs a read-for-size to get the text or binary file size and stores this value on DASD. Subsequent file size requests from clients do not cause the server to read for size, thus improving performance. However, when the data set is modified outside the server by a non-NFS application (for example, by the TSO/E editor), the stored file size could be incorrect. When the data set is accessed again by the server, read-for size must be done to determine the correct file size.

For file size limitations, see sections Creating physical sequential files, Creating direct access files, and Creating PDSs and PDSEs.