Provided by: openafs-fileserver_1.6.15-1ubuntu1.1_amd64 
NAME
BosConfig - Defines server processes for the BOS Server to monitor
DESCRIPTION
The BosConfig file lists the processes that the Basic OverSeer (BOS) Server monitors on
its server machine, and thus defines which AFS server processes run on the machine. It
specifies how the BOS Server reacts when a process fails, and also defines the times at
which the BOS Server automatically restarts processes as part of performance maintenance.
The file must reside in the /var/lib/openafs/local directory on each AFS server machine.
A server process entry in the BosConfig file records the following information:
• The entry type, which is one of the following:
cron
Designates a server process that runs periodically instead of continuously. The
BOS Server starts a cron process only at specified times, not whenever it fails.
All standard AFS process entries except "fs" are simple (there are no standard
cron processes).
fs Designates a group of interdependent server processes. If one of the processes
fails, the BOS Server must coordinate its restart with the restart of the other
processes in the group, possibly by stopping them first.
There is only one standard entry of this type, for which the conventional name is
"fs". It combines three server processes: the File Server (fileserver process),
the Volume Server (volserver process), and the Salvager (salvager process). These
processes all operate on the same data--the AFS data stored on an AFS server
machine's /vicep partitions and mounted in the AFS filespace--but in different
ways. Grouping the processes prevents them from attempting to access the same data
simultaneously, which can cause corruption.
During normal operation, the Salvager process is not active. If the File Server
process fails, however, the BOS Server stops the Volume Server process and runs
the Salvager process to correct any corruption that resulted from the failure.
(The administrator can also issue the bos salvage command to invoke the Salvager
process.) If the Volume Server fails, the BOS Server can restart it without
stopping the File Server or running the Salvager.
simple
Designates a server process that runs independently of any other on the server
machine. If a simple process fails, the BOS Server does not have to coordinate its
restart with any other process.
• The entry name. The conventional name for an entry in the BosConfig file and the
associated process matches the binary filename. When issuing any bos command that
takes the -instance argument, identify each process by the name used in the BosConfig
file. For a list of the names, see the bos create reference page.
• The process's status flag, which determines whether the BOS Server attempts to start
the process in two cases: each time the BOS Server itself restarts, and when the
process fails. The BosConfig file currently uses a binary notation to indicate whether
the BOS Server attempts to restart the process as necessary or does not monitor it at
all. For the sake of clarity, the AFS documentation refers to the flags as "Run" and
"NotRun" instead. Only a system administrator, not the BOS Server, can change the
flag.
• One or more command parameters which the BOS Server invokes to start the process or
processes associated with the entry:
• A "cron" entry has two command parameters, the first the complete pathname to the
program, and the second the time at which the BOS Server invokes the program.
• The "fs" entry has three command parameters, each the complete pathname to the
fileserver, volserver, and salvager programs, in that order.
• A "simple" entry has only one command parameter, the complete pathname to the
program.
In addition to server process entries, the BosConfig file specifies the times at which the
BOS Server performs two types of automatic process restarts:
• The general restart time at which the BOS Server restarts itself and then each process
for which the entry in the BosConfig file has status flag "Run". The default setting
is Sunday at 4:00 a.m.
• The binary restart time at which the BOS Server restarts any server process for which
the time stamp on the binary file in the /usr/lib/openafs directory is later than the
last restart time for the process. The default is 5:00 a.m.
Finally, there is an entry specifying whether the BOS Server will start in restricted
mode.
Although the BosConfig file is in ASCII format, it is normally best not to use a text
editor to alter it. The parser is very picky, and incorrectly formatted entries can
prevent server startup in ways that are difficult to diagnose. Instead, use the
appropriate commands from the bos command suite:
• The bos create command to create an entry in the file and start the associated
process.
• The bos delete command to remove an entry from the file after the bos stop command is
used to stop the associated process.
• The bos getrestart command to display the times at which the BOS Server performs
automatic restarts.
• The bos getrestricted command to display whether the BOS Server is running in
restricted mode.
• The bos setrestart command to set the times at which the BOS Server performs automatic
process restarts.
• The bos setrestricted command to place the BOS Server in restricted mode.
• The bos start command to change an entry's status flag to "Run" and start the
associated process.
• The bos status command to display all processes listed in the file.
• The bos stop command to change an entry's status flag to "NotRun" and stop the
associated process.
There are also bos commands that start and stop processes without changing entries in the
BosConfig file. The BOS Server reads the BosConfig file only when it starts, transferring
the information into its memory. Thus a process's status as represented in the BOS
Server's memory can diverge from its status in the BosConfig file. The following commands
change a process's status in the BOS Server's memory only:
• The bos restart command restarts a specified set of processes, all processes, or all
processes other than the BOS Server.
• The bos shutdown command stops a process.
• The bos startup command starts a process.
When the BOS Server shuts down, it rewrites BosConfig, discarding any changes made
manually to that file. To change the configuration for the next BOS Server restart,
instead write a new file to BosConfig.new. If BosConfig.new exists when the BOS Server
starts, BosConfig will be replaced by BosConfig.new before the BOS Server reads its
configuration. Note that the BOS Server will notice a new BosConfig.new file whenever the
general restart time is reached, if one is configured, since the BOS Server restarts
itself at that time.
SEE ALSO
bos_create(8), bos_delete(8), bos_getrestart(8), bos_getrestricted(8), bos_restart(8),
bos_setrestart(8), bos_setrestricted(8), bos_shutdown(8), bos_start(8), bos_startup(8),
bos_status(8), bos_stop(8), bos_salvage(8), fileserver(8), salvager(8), volserver(8)
COPYRIGHT
IBM Corporation 2000. <http://www.ibm.com/> All Rights Reserved.
This documentation is covered by the IBM Public License Version 1.0. It was converted
from HTML to POD by software written by Chas Williams and Russ Allbery, based on work by
Alf Wachsmann and Elizabeth Cassell.