G06.29 Release Version Update Compendium

Operating System
G06.29 Release Version Update Compendium—542946-001
2-3
Migration
Migration
As of the G06.29 RVU, Version 1 filesets are not supported. You must upgrade Version
1 filesets to Version 2 or Version 3 filesets.
To use OSS ACLs, you must first migrate to the G06.29 RVU and then you must
migrate your existing filesets to Version 3 filesets. To migrate filesets, you must stop
the OSS file system and the OSS environment and use the fsck DIAGNOSE
FILESET, UPGRADE command as described in the Open System Services
Management and Operations Guide.
Fallback
To fall back, you must install the previous SPRs for the OSS products and for DP2. In
addition, in either of these cases, you must run fsck on the fileset to downgrade the
fileset to Version 2:
•
If the fsck utility has been run on a fileset to upgrade to Version 3 filesets
•
If the fileset was created on a system running the G06.29 or later G-series RVU
When the fileset is downgraded to Version 2, any optional ACLs associated with the
files in the fileset are lost.
OSS Files Larger Than 2 GB
As of G06.29, 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 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 existing Enscribe APIs. 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.