postmulti Man page

POSTMULTI(1) General Commands Manual POSTMULTI(1)


postmulti – Postfix multi-instance manager


Enabling multi-instance management:

postmulti -e init [-v]

Iterator mode:

postmulti -l [-aRv] [-g group] [-i name]

postmulti -p [-av] [-g group] [-i name] command…

postmulti -x [-aRv] [-g group] [-i name] command…

Life-cycle management:

postmulti -e create [-av] [-g group] [-i name] [-G group] [-I name] [param=value …]

postmulti -e import [-av] [-g group] [-i name] [-G group] [-I name] [config_directory=/path]

postmulti -e destroy [-v] -i name

postmulti -e deport [-v] -i name

postmulti -e enable [-v] -i name

postmulti -e disable [-v] -i name

postmulti -e assign [-v] -i name [-I name] [-G group]


The postmulti command allows a Postfix administrator to manage mul‐
tiple Postfix instances on a single host.

postmulti implements two fundamental modes of operation. In itera‐
tor mode, it executes the same command for multiple Postfix instances.
In life-cycle management mode, it adds or deletes one instance, or
changes the multi-instance status of one instance.

Each mode of operation has its own command syntax. For this reason,
each mode is documented in separate sections below.

A multi-instance configuration consists of one primary Postfix
instance, and one or more secondary instances whose configuration
directory pathnames are recorded in the primary instance’s
file. Postfix instances share program files and documentation, but have
their own configuration, queue and data directories.

Currently, only the default Postfix instance can be used as primary
instance in a multi-instance configuration. The postmulti command
does not currently support a -c option to select an alternative primary
instance, and exits with a fatal error if the MAIL_CONFIG environment
variable is set to a non-default configuration directory.

See the MULTI_INSTANCE_README tutorial for a more detailed discussion
of multi-instance management with postmulti.

In iterator mode, postmulti performs the same operation on all Postfix
instances in turn.

If multi-instance support is not enabled, the requested command is per‐
formed just for the primary instance.

Iterator mode implements the following command options:

Instance selection
-a Perform the operation on all instances. This is the default.

-g group
Perform the operation only for members of the named group.

-i name
Perform the operation only for the instance with the specified
name. You can specify either the instance name or the absolute
pathname of the instance’s configuration directory. Specify “-”
to select the primary Postfix instance.

-R Reverse the iteration order. This may be appropriate when updat‐
ing a multi-instance system, where “sink” instances are started
before “source” instances.

This option cannot be used with -p.

List mode
-l List Postfix instances with their instance name, instance group
name, enable/disable status and configuration directory.

Postfix-wrapper mode
-p Invoke postfix to execute the specified command. This option
implements the postfix-wrapper(5) interface.

· With “start”-like commands, “postfix check” is executed
for instances that are not enabled. The full list of com‐
mands is specified with the postmulti_start_commands

· With “stop”-like commands, the iteration order is
reversed, and disabled instances are skipped. The full
list of commands is specified with the post‐
multi_stop_commands parameter.

· With “reload” and other commands that require a started
instance, disabled instances are skipped. The full list
of commands is specified with the postmulti_control_com‐
mands parameter.

· With “status” and other commands that don’t require a
started instance, the command is executed for all

The -p option can also be used interactively to start/stop/etc.
a named instance or instance group. For example, to start just
the instances in the group “msa”, invoke postmulti as fol‐

# postmulti -g msa -p start

Command mode
-x Execute the specified command for all Postfix instances. The
command runs with appropriate environment settings for MAIL_CON‐
FIG, command_directory, daemon_directory, config_directory,
queue_directory, data_directory, multi_instance_name,
multi_instance_group and multi_instance_enable.

Other options
-v Enable verbose logging for debugging purposes. Multiple -v
options make the software increasingly verbose.

With the -e option postmulti can be used to add or delete a Postfix
instance, and to manage the multi-instance status of an existing

The following options are implemented:

Existing instance selection
-a When creating or importing an instance, place the new instance
at the front of the secondary instance list.

-g group
When creating or importing an instance, place the new instance
before the first secondary instance that is a member of the
specified group.

-i name
When creating or importing an instance, place the new instance
before the matching secondary instance.

With other life-cycle operations, apply the operation to the
named existing instance. Specify “-” to select the primary
Postfix instance.

New or existing instance name assignment
-I name
Assign the specified instance name to an existing instance,
newly-created instance, or imported instance. Instance names
other than “-” (which makes the instance “nameless”) must start
with “postfix-“. This restriction reduces the likelihood of
name collisions with system files.

-G group
Assign the specified group name to an existing instance or to a
newly created or imported instance.

Instance creation/deletion/status change
-e action
“Edit” managed instances. The following actions are supported:

init This command is required before postmulti can be used
to manage Postfix instances. The “postmulti -e init”
command updates the primary instance’s file by

multi_instance_wrapper =
${command_directory}/postmulti -p —
multi_instance_enable = yes

You can set these by other means if you prefer.

create Create a new Postfix instance and add it to the
multi_instance_directories parameter of the primary
instance. The “-I name” option is recommended to give
the instance a short name that is used to construct
default values for the private directories of the new
instance. The “-G group” option may be specified to
assign the instance to a group, otherwise, the new
instance is not a member of any groups.

The new instance is the stock with the
parameters that specify the locations of shared files
cloned from the primary instance. For “nameless”
instances, you should manually adjust “syslog_name” to
yield a unique “logtag” starting with “postfix-” that
will uniquely identify the instance in the mail logs. It
is simpler to assign the instance a short name with the
“-I name” option.

Optional “name=value” arguments specify the instance con‐
fig_directory, queue_directory and data_directory. For

# postmulti -I postfix-mumble \
-G mygroup -e create \
config_directory=/my/config/dir \
queue_directory=/my/queue/dir \

If any of these pathnames is not supplied, the program
attempts to generate the pathname by taking the corre‐
sponding primary instance pathname, and by replacing the
last pathname component by the value of the -I option.

If the instance configuration directory already exists,
and contains both a and file, create
will “import” the instance as-is. For existing instances,
create and import are identical.

import Import an existing instance into the list of instances
managed by the postmulti multi-instance manager. This
adds the instance to the multi_instance_directories list
of the primary instance. If the “-I name” option is pro‐
vided it specifies the new name for the instance and is
used to define a default location for the instance con‐
figuration directory (as with create above). The “-G
group” option may be used to assign the instance to a
group. Add a “config_directory=/path” argument to over‐
ride a default pathname based on “-I name”.

Destroy a secondary Postfix instance. To be a candidate
for destruction an instance must be disabled, stopped and
its queue must not contain any messages. Attempts to
destroy the primary Postfix instance trigger a fatal
error, without destroying the instance.

The instance is removed from the primary instance
file’s alternate_config_directories parameter and its
data, queue and configuration directories are cleaned of
files and directories created by the Postfix system. The and files are removed from the configu‐
ration directory even if they have been modified since
initial creation. Finally, the instance is “deported”
from the list of managed instances.

If other files are present in instance private directo‐
ries, the directories may not be fully removed, a warning
is logged to alert the administrator. It is expected that
an instance built using “fresh” directories via the cre‐
ate action will be fully removed by the destroy action
(if first disabled). If the instance configuration and
queue directories are populated with additional files
(access and rewriting tables, chroot jail content, etc.)
the instance directories will not be fully removed.

The destroy action triggers potentially dangerous file
removal operations. Make sure the instance’s data, queue
and configuration directories are set correctly and do
not contain any valuable files.

deport Deport a secondary instance from the list of managed
instances. This deletes the instance configuration direc‐
tory from the primary instance’s multi_instance_directo‐
ries list, but does not remove any files or directories.

assign Assign a new instance name or a new group name to the
selected instance. Use “-G -” to specify “no group” and
“-I -” to specify “no name”. If you choose to make an
instance “nameless”, set a suitable syslog_name in the
corresponding file.

enable Mark the selected instance as enabled. This just sets the
multi_instance_enable parameter to “yes” in the
instance’s file.

Mark the selected instance as disabled. This means that
the instance will not be started etc. with “postfix
start”, “postmulti -p start” and so on. The instance can
still be started etc. with “postfix -c config-directory

Other options
-v Enable verbose logging for debugging purposes. Multiple -v
options make the software increasingly verbose.

The postmulti command exports the following environment variables
before executing the requested command for a given instance:

This is set when the -v command-line option is present.

The location of the configuration directory of the instance.



config_directory (see ‘postconf -d’ output)
The default location of the Postfix and con‐
figuration files.

daemon_directory (see ‘postconf -d’ output)
The directory with Postfix support programs and daemon programs.

import_environment (see ‘postconf -d’ output)
The list of environment parameters that a Postfix process will
import from a non-Postfix parent process.

multi_instance_directories (empty)
An optional list of non-default Postfix configuration directo‐
ries; these directories belong to additional Postfix instances
that share the Postfix executable files and documentation with
the default Postfix instance, and that are started, stopped,
etc., together with the default Postfix instance.

multi_instance_group (empty)
The optional instance group name of this Postfix instance.

multi_instance_name (empty)
The optional instance name of this Postfix instance.

multi_instance_enable (no)
Allow this Postfix instance to be started, stopped, etc., by a
multi-instance manager.

postmulti_start_commands (start)
The postfix commands that the postmulti instance manager
treats as “start” commands.

postmulti_stop_commands (see ‘postconf -d’ output)
The postfix commands that the postmulti instance manager
treats as “stop” commands.

postmulti_control_commands (reload flush)
The postfix commands that the postmulti instance manager
treats as “control” commands, that operate on running instances.

syslog_facility (mail)
The syslog facility of Postfix logging.

syslog_name (see ‘postconf -d’ output)
The mail system name that is prepended to the process name in
syslog records, so that “smtpd” becomes, for example, “post‐

Available in Postfix 3.0 and later:

meta_directory (see ‘postconf -d’ output)
The location of non-executable files that are shared among mul‐
tiple Postfix instances, such as postfix-files,,
and the multi-instance template files and mas‐

shlib_directory (see ‘postconf -d’ output)
The location of Postfix dynamically-linked libraries (libpost‐
fix-*.so), and the default location of Postfix database plugins
(postfix-*.so) that have a relative pathname in the dynam‐ file.

$meta_directory/, stock configuration file
$meta_directory/, stock configuration file
$daemon_directory/postmulti-script, life-cycle helper program


postfix, Postfix control program
postfix-wrapper(5), Postfix multi-instance API

Use “postconf readme_directory” or “postconf html_directory” to locate
this information.
MULTI_INSTANCE_README, Postfix multi-instance management

The postmulti command was introduced with Postfix version 2.6.

The Secure Mailer license must be distributed with this software.

Victor Duchovni
Morgan Stanley

Wietse Venema
IBM T.J. Watson Research
P.O. Box 704
Yorktown Heights, NY 10598, USA