Using Daemons, Processes, and Tracing

Understanding system daemons and processes is useful when you are debugging. This section describes the Sun SAM and Sun QFS daemons and processes. It also provides information about daemon tracing.

Daemons and Processes

All daemons are named in the form sam-daemon_named. Processes are named in a similar manner, except that processes do not end in the lowercase letter d.

The following table shows some of the daemons and processes that can run on your system. Others, such as sam-genericd and sam-catserverd, might also be running, depending on system activities.

Table 7-1 Daemons and Processes

When you run the software, SMF starts the sam-fsd daemon. It should restart automatically in case of failure.

In a shared file system, a sam-fsd daemon is always active. In addition, one sam-sharefsd daemon is active for each mounted shared file system.

When a shared file system is mounted, the software starts a shared file system daemon (sam-sharefsd). TCP sockets are used to communicate between the server and client hosts. All clients that connect to the metadata server are validated against the hosts file. See the hosts.fs(4) man page for more information about the hosts file.

The sam-sharedfsd daemon on the metadata server opens a listener socket on the port named sam-qfs. During the Sun QFS installation process, the sam-qfs entry is automatically added to /etc/services file. Do not remove this entry. In addition, the shared file system port is defined in the /etc/inet/services file as port number 7105. Verify that this port does not conflict with another service.

All metadata operations, block allocation and deallocation, and record locking are performed on the metadata server. The sam-sharefsd daemon does not keep any information. Hence, it can be stopped and restarted without causing any consistency problems for the file system.

Trace Files

Several processes can write messages to trace files. These messages contain information about the state and progress of the work performed by the daemons. The messages are primarily used by Oracle support staff to improve performance and diagnose problems. The message content and format are subject to change from release to release.

Trace files can be used in debugging. By default, trace files are not enabled. You can enable trace files by editing the defaults.conf file. You can enable tracing for all processes, or you can enable tracing for individual processes. For information about the processes that you can trace, see defaults.conf(4) in Sun QFS and Sun Storage Archive Manager 5.3 Reference Manual.

By default, trace files are written to the /var/opt/SUNWsamfs/trace directory. In that directory, the trace files are named for the processes (archiver, catserver, fsd, ftpd, recycler, sharefsd, and stager). You can change the names of the trace files by specifying directives in the defaults.conf configuration file. You can also set a limit on the size of a trace file and rotate your tracing logs. For information about controlling tracing, see defaults.conf(4) in Sun QFS and Sun Storage Archive Manager 5.3 Reference Manual.

Trace File Content

Trace file messages contain the time and source of the message. The messages are produced by events in the processes. You can select the events by using directives in the defaults.conf file.

The default events are as follows:

• Customer notification syslog or notify file messages

• Nonfatal program errors

• Fatal syslog messages

• Process initiation and completion

• Other miscellaneous events

You can also trace the following events:

• Memory allocations

• Interprocess communication

• File actions

• Operator messages

• Queue contents when changed

• Other miscellaneous events

The default message elements (program name, process ID (PID), and time) are always included and cannot be excluded. Optionally, the messages can also contain the following elements:

• The date. (The time is always included.)

• The source file name and line number.

• The event type.

Trace File Rotation

To prevent trace files from growing indefinitely, the sam-fsd daemon monitors the size of the trace files and periodically executes the following command:

/opt/SUNWsamfs/sbin/trace_rotate

This script moves the trace files to sequentially numbered copies. You can modify this script to suit your operation. Alternatively, you can provide this function using cron or some other facility.

Determining Which Processes Are Being Traced

To determine which processes are being traced currently, issue the sam-fsd command at the command line. The following example shows the output from this command.

Example 7-1 sam-fsd Command Output

# sam-fsd
Trace file controls:
sam-amld      /var/opt/SUNWsamfs/trace/sam-amld
             cust err fatal misc proc date
             size    10M  age 0
sam-archiverd /var/opt/SUNWsamfs/trace/sam-archiverd
             cust err fatal ipc misc proc queue date module
             size    10M  age 0
sam-catserverd /var/opt/SUNWsamfs/trace/sam-catserverd
             cust err fatal misc proc date
             size    10M  age 0
sam-dbupd     /var/opt/SUNWsamfs/trace/sam-dbupd
             cust err fatal misc proc date
             size    10M  age 0
sam-fsalogd   /var/opt/SUNWsamfs/trace/sam-fsalogd
             cust err fatal misc proc date
             size    10M  age 0
sam-fsd       /var/opt/SUNWsamfs/trace/sam-fsd
             cust err fatal misc proc date
             size    10M  age 0
sam-rftd      /var/opt/SUNWsamfs/trace/sam-rftd
             cust err fatal misc proc date
             size    10M  age 0
sam-recycler  /var/opt/SUNWsamfs/trace/sam-recycler
             cust err fatal ipc misc proc date module type
             size    10M  age 0
sam-nrecycler /var/opt/SUNWsamfs/trace/sam-nrecycler
             cust err fatal misc proc date
             size    10M  age 0
sam-sharefsd  /var/opt/SUNWsamfs/trace/sam-sharefsd
             cust err fatal misc proc date
             size    10M  age 0
sam-stagerd   /var/opt/SUNWsamfs/trace/sam-stagerd
             cust err fatal ipc misc proc date module
             size    10M  age 0
sam-serverd   /var/opt/SUNWsamfs/trace/sam-serverd
             cust err fatal misc proc date
             size    10M  age 0
sam-clientd   /var/opt/SUNWsamfs/trace/sam-clientd
             cust err fatal misc proc date
             size    10M  age 0
fsmgmt        /var/opt/SUNWsamfs/trace/fsmgmt
             cust err fatal misc proc date
             size    10M  age 0
sam-shrink    /var/opt/SUNWsamfs/trace/sam-shrink
             cust err fatal misc proc date
             size    10M  age 0
Would start sam-archiverd()
Would start sam-stagealld()
Would start sam-stagerd()
Would start sam-amld()
# 

For more information about enabling trace files, see defaults.conf(4) in Sun QFS and Sun Storage Archive Manager 5.3 Reference Manual and sam-fsd(1M) in Sun QFS and Sun Storage Archive Manager 5.3 Reference Manual.