2. s/qmail file system usage
s/qmail 'populates' the same system file space as Qmail. Thus the default directory is
- /var/qmail/
However, since s/sqmail follows the /package principals, there some differences, one should recognize.
Beyond that main directory, the following subdirectories are raised:
- /var/qmail/alias/: alias directory
- /var/qmail/bin/: directories of executables (binaries and scripts)
- /var/qmail/control/: directory homing the control files
- /var/qmail/ssl/: directory to store X.509 certs, key files and other files required for ucspi-ssl to work
- /var/qmail/users/: sqmail user and recipients
Note: The s/qmail binary files and scripts posses a compiled-in path and are not subject of environment variables for those.
Optional directories are:
- /var/qmail/etc: ucspi-ssl and ucspi-tcp6 configuration files
- /var/qmail/skeletons: QMQ skeleton directory
- /var/qmail/svc: supervise directory for /service daemons
2.1 Queue directory
The queue directory needs to reside on a contiguous directory, since s/sqmail uses inodes as file name: The file name is equal to its inode. Currently, this can only achieved on the very same file system.
A typical queue layout should show up in the following way:
The directories
- info,
- intd,
- local,
- mess,
- remote,
- todo, and now
- dkim
posses a number of sub-directories according to conf-split which defaults to '23'. Messages are equally distributed in here for performance reasons.
The spliting of todo corresponds to the BIGTODO feature and supports qmail-send operation to move a file from the TODO (pending) state to the actual execution state, even for a very large message number without significant performance degradation due to stat bottlenecks.
2.3 Binary directories
After installation, the executable s/sqmail files can be found in the following directories:
- /var/qmail/bin/: These files belong to the s/qmail instance and act upon the current ./queue/.
- /usr/local/bin/: s/qmail files here are 'general purpose' and are for applicable for all s/qmail instances.
2.4 Control directory
s/qmail control directory is used by
Currently, s/qmail does not differentiate between a
- configuration and
- control file.
A configuration file es read upon the start of a service and perhaps by a certain signal, while a control file is taken into account by a service for a session/transaction, thus is read on-the-fly.
In general qmail-send reads it's control files on invocation (except for locals, virtualdomains, concurrencylocal and concurrencyremote which can be actived sending a HUP signal to qmail-send. All other control files are processed on-the-fly, however messages already prepared for sending, are not affected a posteriori changing a control file.
The current settings of the control files can be evaluated by means of the qmail-showctl command. The default settings are described in qmail-control.
2.5 User directory
The ./user/ directory of s/qmail serves three different purposes:
- To assign local Unix users with email addresses by means of qmail-users,
- to serve as default location for qmail-recipients where the file users/recipients is compiled to a cdb for valid email addresses to accept by qmail-smtpd.
- to store the authuser file for SMTP and/or POP3 authentication required for qmail-smtpd, qmail-popup and read by qmail-authuser.
2.6 etc directory
The ./etc directory is an 'alien' directory for s/qmail. Typically it is used to store
configuration databases, the '*.cdb' files.
However, these files are indispensible for the running s/qmail system and the should belong to a particular instance. Therefore, this is the place to live!