H06.06 Release Version Update Compendium

Operating System
H06.06 Release Version Update Compendium—542486-001
2-2
OSS Files Larger Than 2 GB
OSS Files Larger Than 2 GB
As of H06.06, NonStop Open System Services (OSS) supports files larger than the
previous limit of approximately 2 gigabytes (GB) in the OSS file system, DP2, C run-
time library, C++ run-time library, COBOL run-time library, and the OSS utilities. The
OSS file system and utilities can handle OSS files up to a limit of 1 terabyte, although
the upper limit of the actual file size depends on the size of the volume containing the
file.
OSS files are created with an underlying Guardian file format of Format 2 whenever
creation is requested through a 64-bit API. Existing OSS files are converted to an
underlying Guardian file format of Format 2 the first time they are accessed by either
the new OSS 64-bit APIs or Enscribe. Any program that uses the existing 32-bit APIs
can open and access any OSS files smaller than approximately 2 GB.
Large OSS File Aware and Large OSS File Safe Applications
An application that is large OSS file aware (LFA) can process OSS files larger than 2
GB with the same functionality as processing OSS files smaller than 2 GB. Such an
application is capable of handling large files as input and generating large files as
output.
An application that is large OSS file safe (LFS) causes no data loss or corruption when
it encounters an OSS file larger than 2 GB. It might not have the capability to process
OSS files larger than 2 GB, but it has the appropriate logic to handle errors or warnings
detected during file manipulation operations and fail gracefully.
As of H06.06, these SUT-based applications are large OSS file aware:
•
Backup/Restore 2
•
DSAP/DCOM
•
FUP
•
iTP Webserver
•
FTP
•
C/C++ compiler
•
Cobol compiler
•
OSS utilities and unsupported utilities
•
NonStop SQL/MX utilities (IMPORT and EXPORT DDL)
All other OSS applications (including utilities, tools, or libraries) are large OSS file safe
for H06.06 and later RVUs.
Large OSS File Aware and Large OSS File Safe APIs
To support OSS files larger than 2 GB, new 64-bit file I/O APIs are available. These
APIs can handle files larger than 2 GB and files smaller than 2 GB. The large OSS file
aware I/O APIs include:
•
creat64()
•
open64()