2.4.3 Recovery when installation fails
If package installation fails, both the distributed package (the new version) and the package already installed (the old version) become unusable. In such situations, you can use the recovery facility to restore the old version of the package.
- Organization of this subsection
(1) Overview of recovery
To use the recovery facility, you must specify usage at packaging time. You can also specify whether to keep the backup if recovery fails or is not executed.
When a package is distributed with recovery specified, the distribution-destination system backs up the old version before installing the package. If installation fails, the old version is restored from the backup. If recovery is successful, the backup is deleted. Also, the backup is deleted if recovery is not executed (if installation completed normally).
(2) Preparation at distribution-destination systems
To use the recovery facility, a directory for backup files must be created on each distribution-destination system. For details on creating a directory, see 5.9 Creating the backup directory in PART 2.
Each distribution-destination system must also have sufficient disk space to back up the old version. Estimate the capacity required for the backup, and make sure that the recovery facility is operable at each system. For details on estimating the disk space required for recovery, see 5.2 Estimating of the disk space and memory requirements in PART 2.
(3) Optional backup of user data and programs
The backup facility always backs up files that will be overwritten on the distribution-destination systems. In addition, you can optionally back up user data and user programs distributed as packages. To specify backup of user data and user programs, create a backup list defining the files and directories that you want to back up. Specify the prepared backup list at packaging time. When a backup list is specified for a package installed on a distribution-destination system, backup will be taken, as specified in the backup list, at distribution of the next version with the recovery facility enabled. For details on creating a backup list, see 6.2.1 Acquiring backups in PART 2.
(4) Recovery restrictions
If either of the following errors occurs, the old version is backed up, but recovery is not executed:
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A Hitachi program product was successfully installed, but a setup error occurred.
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A timeout occurred at package installation with external program processing before or after package installation.
If the backed-up old version was kept, you can retry recovery in such cases. Also, if you keep the backup, you can retry if recovery fails. Retry can be specified at the managing server or at the distribution-destination system. For details on retrying recovery, see 9.2.1(3) Failures in the recovery facility in PART 4.
Note that some Hitachi program products might not support recovery, depending on the program attributes. Recovery will not be executed even if specified for such Hitachi program products. Also note that, for another company's software, only the HP-UX version supports recovery.