H06.08 Software Installation and Upgrade Guide

H06.08 Installation, Migration, and Fallback
Considerations
H06.08 Software Installation and Upgrade Guide—543573-001
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Backup and Restore 2 Fallback
Fallback
The H06.06 and later versions of DSAP/DCOM (T9543H01^ABH) are large OSS file
safe, but pre-H06.06 versions are not. If you fall back from H06.06 or later to an earlier
RVU, HP recommends that you install T9543H01^ABH during the fallback.
Backup and Restore 2 Fallback
OSS files larger than 2 GB that have been backed up cannot be restored to a pre-
H06.06 system. Install the Backup and Restore 2 fallback SPR T0744H01^AAA to
restore files smaller than 2 GB in the following situations:
•
If you have a backup tape with a mix of OSS files smaller than 2 GB and larger
than 2 GB. You can restore the smaller files to an H06.05 file set by first installing
T0744H01^AAA.
•
If you have created backup tapes on H06.08 and you are falling back to H06.05.
Files larger than 2 GB are skipped. T0744H01^AAA does not support pre-H06.05
RVUs.
Guardian Compatibility Issue
OSS support for files greater than 2 GB has resulted on a compatibility issue for
applications using Enscribe APIs to access Guardian files created by OSS APIs.
Prior to the H06.06 RVU, Guardian files created by OSS APIs were always created as
Format 1 with a 175 MB maximum size. As of H06.06, Guardian files created by the
open() and creat() functions are Format 1 with an approximate 2 GB maximum
size, and Guardian files created by the open64() and creat64() functions are
Format 2 with an approximate 26 GB maximum size.
The standard OSS utilities, such as cp, pax, and pinstall, now use open64() and
creat64(), and thus create a Guardian Format 2 file when given a /G output file
name. For example:
cp myfile /G/mydisk/mysubvol/myfile
Guardian applications that use file data and ignore file attributes are unaffected. An
application that performs a 32-bit FILE_OPEN_ of a Format 1 file will successfully open
a Format 2 file as long as the file’s EOF is less than the Format 1 limit of approximately
4 GB.
Guardian applications that use file attributes such as file format and maximum size are
likely to be affected. These programs might fail when unexpected values are returned
(such as Format 2 if only Format 1 is expected).
Note. An application that is “large file safe” causes no data loss or corruption when it
encounters an OSS file larger than 2 GB. It may not necessarily 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.