Software Distributor Administration Guide (March 2009)

depot specified by swagent.alternate_source. An alternate source is specified
using the host:/path, /path, or host syntax.
• If there is a host:/depot_path specified in the target’s
swagent.alternate_source option, the agent gets the software from this
source. If only a host is specified, the target agent uses the same depot path
used by the controller.
• If the target doesn’t have an alternate source, the agent uses the same depot
path used by the controller, but it will apply this path to its own file system.
This lets you do staged installations without any target configuration at all,
by locating the intermediate depot on each target system at the same file
system location as the master depot (approach 2 above).
Because the swcopy and swinstall steps in a staged installation are separate, SD-UX
cannot enforce consistency between master and intermediate depots. You must ensure
that the software available from the intermediate depots is consistent with that on the
master depot.
If master and intermediate depots are out-of-synch when you perform the swinstall
step, you may encounter errors if software that is on the master depot is not available
from one or more intermediate depots.
8.10 Recovery (Install Only)
NOTE: This section applies only to customer-created software with unpreinstall and
unpostinstall scripts. HP-supplied software does not include these scripts.
SD-UX supports automatic procedures to recover from failed installation if the
autorecover_product option is set to true, attempting to leave the system in the
same state as it was previously. Also, manual means are available (refer to “Multiple
Versions ” (page 179)).
Rollback is limited to the system where the installation of the product failed, not all
target systems specified in an installation job.
Because autorecovery removes any files that were installed up to this point, it is
antithetic with the checkpointing and retry features previously described. Recovery
saves copies of each file that it is replacing, then removes those files at the successful
completion of the product installation. If the install fails, then the saved files are restored.
Once a product is successfully updated, it cannot be restored except by reinstalling it.
Additionally, if a later product fails, the earlier product cannot be recovered. In order
to meet the requirement that multiple products be recoverable, multiple versions must
be installed.
The unpreinstall and unpostinstall scripts are needed to undo the steps that the preinstall
and postinstall scripts executed. The normal sequence of operations for each product
is:
178 Reliability and Performance