The File Alteration Monitor (fam) is a daemon that monitors files and directories. Application writers can include certain function calls in their applications to let fam know that they want to be informed of changes to whichever files and/or directories they specify. For example, mailbox(1) uses fam to know when to indicate the arrival of new mail. The fam daemon runs only when applications using it are running; it exits after all programs using it have stopped. For additional information about fam usage, see the fam(1M) and fam(3X) man pages.
Beginning with the IRIX 6.5.8 release, you can use a configuration file, in addition to the command-line options, to control fam behavior. By default, this file is called/etc/fam.conf; you can enter the -c command-line option to specify an alternate file.
Configuration lines are in the format option=value as shown in Example 8-1. Lines beginning with # or ! are ignored. The daemon recognizes the insecure_compatibility, untrusted_user, local_only, and xtab_verification options illustrated in the default file. For a description of these options, see the fam(1M) man page.
Example 8-1. Default fam.conf File
# fam.conf # # For more information on the configuration options below, see the # fam(1M) man page. # # insecure_compatibility disables authentication. This causes # untrusted_user to be ignored, because the UID presented by every # client connection will be believed. # # The -C command-line argument overrides this option. # insecure_compatibility = false # # untrusted_user is the user which will be used for unauthenticated # clients. If a file can't be stat'ed by this user, those clients # won't be able to fam it. The value can be a user name or a # numeric UID. # untrusted_user = nobody # # # local_only makes fam ignore requests from remote clients & remote # fams. Note that this is ignored if fam is started by inetd. # # The -L command-line argument overrides this option. # local_only = false # # xtab_verification makes fam check the list of exported filesystems # to verify that requests from remote hosts fall on filesystems # which are exported to the hosts. # xtab_verification = true |
Sometimes, when attempting to start up an application that uses fam, an error message is displayed:
Cannot connect with File Alteration Monitor (fam) |
There are several reasons why this message appears. This section describes some of the common ways to troubleshoot the problem.
If you see one of the following two messages on your screen, follow the steps in Procedure 8-1:
Can't connect to fam Cannot connect with File Alteration Monitor (fam) |
Procedure 8-1. Troubleshooting fam
Check the /var/adm/SYSLOG file (the system log) for useful messages. For instructions on using the sysmon tool, see “sysmon, the System Log Viewer” in Chapter 2.
See if fam is running with the following ps command:
ps -ef | grep fam
If fam is running, verify that it was started by inetd. The parent PID (PPID) listed for the fam process should match the PID returned by the following ps command:
ps -ef | grep inetd
If fam is not running, that does not necessarily indicate a problem. The fam daemon is normally started by inetd when an application needs it, and fam only runs as long as it is being used by one or more client applications.
Verify that fam is listed in the /etc/inetd.conf file.
Run the following grep command:
grep fam /etc/inetd.conf
Look for output similar to the following:
sgi_fam/1-2 stream rpc/tcp wait root ?/usr/etc/fam fam
The fam daemon is /user/etc/fam.
If that line is not present, add it, and make inetd reread the file by running the following killall command:
killall -HUP inetd
Verify that the fam daemon is present and executable by root. That is, the /usr/etc/fam file. If the file is not found, you must reinstall the eoe.sw.base subsystem.
Verify that fam is listed in the /etc/rpc file:
Run the following grep command:
grep fam /etc/rpc
Look for output similar to the following:
sgi_fam 391002
Verify that inetd is running with the following ps command:
ps -ef | grep inetd
Look for a response similar to the following:
root 214 1 0 Oct 24 ? 0:01 /usr/etc/inetd
If the following message is displayed, it is a sign that the network is not active.
portmapper failure
For information on network administration, see IRIX Admin: Networking and Mail .
Verify that fam is registered with portmapper by using the rpcinfo command:
rpcinfo -p | grep fam
When inetd reads the /etc/inetd.conf file, it registers the RPC services it finds (such as fam) with the portmapper so that client applications can connect to specific ports for the services they need.
Look for output similar to the following:
391002 1 tcp 1033 sgi_fam 391002 2 tcp 1033 sgi_fam
If the rpcinfo command does not produce any output, then fam is not registered with the portmapper. If you have performed the previous steps (including killall -HUP inetd), it is possible that the portmapper is not running.
Verify that inetd or fam is indeed listening on the registered ports.
In the sample output above, the port is 1033. To find out which processes are listening on it, run the fuser command:
fuser 1033/tcp
If you see the following output, processes 223 and 627 have port 1033 open.
1033/tcp: 223o 627o
Use the ps command to determine whether those processes are inetd and fam.
On the other hand, if the fuser output is more like the following, then the portmapper information is confused and the network services probably needs to be restarted.
1033/tcp: fuser: No such file or directory
If everything else looks like fam should be receiving connections, try turning on fam debugging by adding the -d option to the fam entry in /etc/inetd.conf. The edited line should be similar to the following:
sgi_fam/1-2 stream rpc/tcp wait root ?/usr/etc/fam fam -d
After editing the inetd.conf file, make inetd reread the file by running the killall command:
killall -HUP inetd
If fam is still running (as will be the case if it is still being used by at least one application), restart it so that the debugging flag takes effect:
killall fam
The debugging information is written in the /var/adm/SYSLOG file. This file can be conveniently viewed with the sysmon tool, described in “sysmon, the System Log Viewer” in Chapter 2.
Note: Terminating fam while applications are using it may cause problems for those applications. If possible, terminate those applications first. Note: If you are using a foreign NIS master system, see “Troubleshooting fam When Using a Sun NIS Master”. Note: In the IRIX 6.5.8 release, fam treats clients as untrusted until they have authenticated themselves by proving that they are who they claim to be. Because libfam is a static archive (meaning it is compiled into each client, rather than being a shared library that can be replaced with a version that performs authentication), clients linked with the old libfam may not work correctly when trying to communicate with a new fam. For more information on troubleshooting client applications, see the fam(1M) man page.
If you have the optional NIS (YP) software installed at your site, and you are using a Sun system as your NIS master, with no rpc entries for sgi_toolkitbus and sgi_fam, this section provides the information to correct the error message.
Depending on the operating system (the Sun 3.x or the Sun 4.0) on the Sun NIS (YP) server, one of the two following solutions applies.
Sun 3.x
If the Sun workstation is running version 3.x of Sun/OS, add two entries to the /etc/rpc database on the Sun NIS server. They are:
sgi_toolkitbus 391001
sgi_fam 391002
On the NIS server, enter the command:
cd /usr/etc/yp; make rpc
This may take as much as an hour before the NIS server pushes this information to its clients.
Sun 4.0
If the Sun workstation is running version 4.0 of Sun/OS or later, add two entries to the /etc/rpc database on the Sun NIS server machine. They are:
sgi_toolkitbus 391001
sgi_fam 391002.
On the NIS server, type:
cd /var/yp; make rpc
It may take as much as an hour before the NIS server pushes this information to its clients.
Note: If the NIS system is neither SGI or Sun server, the same rpc entries must be added, but the syntax may be different.