The standard way to install software onto multiple
targets is to specify a single source depot and each target that is
to receive the software. However, some software distribution environments
require that you manage software on large numbers of geographically
dispersed target systems. This may require the use of one or more
intermediate source depots or staging areas. This variant on the standard
model is referred to as a staged installation.
There are two reasons for using a staged installation:
Minimize the amount of
data transferred across a slow and expensive segment of your network.
More easily ensure a successful
installation on all targets by reducing the risk of an unreliable
segment in your network.
If your environment has targets organized in separate,
local area networks (LAN) and connected via a low-throughput, less-reliable
wide area network (WAN), staging software to intermediate depots that
are local to each grouping of targets and then doing the installation
using these intermediate depots reduces the amount of data that travels
over the WAN segment.
By doing so, you also decrease the likelihood
that a problem with the WAN will interrupt the installation step.
Before you do a staged installation, you must
first decide where the intermediate depots should reside. Here are
two possible approaches:
If the targets are grouped,
you can put an intermediate depot on one system in each group and
configure the other targets to use it as their alternate source. This
approach requires that each target in the group be configured to use
the designated intermediate depot.
If making sure that installations
succeed is of highest importance, you can locate the intermediate
depots on the targets themselves, one-per-target. An advantage to
this approach is that it doesn’t necessarily require that you
configure an alternate source on each target. However, this approach
requires that each target system have enough disk space to accommodate
the intermediate depot.
To do a staged installation:
First, decide on the location
of the intermediate depots and use the swcopy command
to copy the software from your master depot to them. This step is
no different from a normal multi-target copy operation.
swcopy -s master -t depot_list NewApp
In this example, the master source depot containing
the product NewApp is in the default /var/spool/sw depot location and a file named depot_list contains the list of intermediate depots.
The depot_list could identify the designated intermediate depots that have been
configured for each group of targets, or it could identify an intermediate
depot located on each target.
Next, use the swinstall command combined with the option use_alternate_source=true to do the actual installation.
The use_alternate_source option is
specified from either the CLI (i.e., -x use_alternate_source=true) or via the Options Editor window in the GUI. The default value
is false.
# swinstall -s master \
-x use_alternate_source=true \
-t targ_list NewApp |
The use_alternate_source=true option instructs each target to use its own configured source for
the installation. The source that is specified on the swinstall CLI is used only by the controller for the validation of your software
selections. The file targ_list contains the list
of targets.
When use_alternate_source is true, each target agent looks for the corresponding swagent.alternate_source option in its own defaults
file. The protocol sequence and endpoint given by the option, swagent.rpc_binding_info, are used when the agent
attempts to contact the 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.