The following sections describe conditions you should be aware of if
you interoperate with RSX-11 or if you use RSX-11 software on your
OpenVMS system.
File System $QIO Interface
The file system $QIO interface supports several attributes for RSX-11
compatibility. Of these, ATR$C_EXPDAT and ATR$C_ASCDATES return the
file creation date, revision date, and expiration date using 2-digit
years.
These attributes are not normally used by native code and can be
replaced with the following documented, compliant interfaces:
- ATR$C_CREDATE
- ATR$C_EXPDATE
- ATR$C_REVDATE
The file system $QIO interface is provided by the following file
systems:
- DIGITAL TCP/IP Network File System (NFS) client
- Distributed File System (DECdfs)
- Magnetic tape ACP
- OpenVMS ODS-1 file system
- OpenVMS ODS-2 file system
- Spiralog file system (Version 7.1, Alpha only)
ODS-1 File Header Format and Utility Support
For RSX-11 compatibility, OpenVMS VAX supports ODS-1 file format disk
volumes. The ODS-1 file system uses a 2-digit year format internally,
and current implementations have limitations for the year 2000.
The magnetic tape ACP also returns an ODS-1 format file header in
response to an application request for the ATR$C_HEADER attribute. This
feature is supported on both VAX and Alpha.
ODS-1 data structures use a 2-digit year ( ddmmyy) in the
following items:
- ODS-1 file header:
- FI1$T_CREDATE
- FI1$T_CRETIME
- FI1$T_EXPDATE
- FI1$T_REVDATE
- FI1$T_REVTIME
- ODS-1 home block: HM1$T_CREDATE
The OpenVMS file system and the following OpenVMS utilities that
support the ODS-1 file system format have been modified to correctly
interpret these 2-digit years until the year 2057:
- Analyze/Disk_Structure Utility
- Backup Utility
- Dump Utility
- Librarian (LBR) routines
Note
Even though we are updating the ODS-1 code for the year 2000,
Compaq
strongly recommends that users of ODS-1 formatted media move to a newer
file format by the year 2000.