System Administration Guide: Advanced Administration

Viewing System Messages

System messages display on the console device. The text of most system messages look like this:

[ID msgid facility.priority]

For example:

[ID 672855 kern.notice] syncing file systems...

If the message originated in the kernel, the kernel module name is displayed. For example:

Oct 1 14:07:24 mars ufs: [ID 845546 kern.notice] alloc: /: file system full 

When a system crashes, it might display a message on the system console like this:

panic: error message

Less frequently, this message might be displayed instead of the panic message:

Watchdog reset !

The error logging daemon, syslogd, automatically records various system warnings and errors in message files. By default, many of these system messages are displayed on the system console and are stored in the /var/adm directory. You can direct where these messages are stored by setting up system message logging. For more information, see Customizing System Message Logging. These messages can alert you to system problems, such as a device that is about to fail.

The /var/adm directory contains several message files. The most recent messages are in /var/adm/messages file (and in messages.*), and the oldest are in the messages.3 file. After a period of time (usually every ten days), a new messages file is created. The messages.0 file is renamed messages.1, messages.1 is renamed messages.2, and messages.2 is renamed messages.3. The current /var/adm/messages.3 file is deleted.

Because the /var/adm directory stores large files containing messages, crash dumps, and other data, this directory can consume lots of disk space. To keep the /var/adm directory from growing too large, and to ensure that future crash dumps can be saved, you should remove unneeded files periodically. You can automate this task by using the crontab file. For more information on automating this task, see How to Delete Crash Dump Files and Chapter 8, Scheduling System Tasks (Tasks).

ProcedureHow to View System Messages

  1. Display recent messages generated by a system crash or reboot by using the dmesg command.

    $ dmesg

    Or, use the more command to display one screen of messages at a time.

    $ more /var/adm/messages

Example 15–1 Viewing System Messages

The following example shows output from the dmesg command.

$ dmesg
Jan  3 08:44:41 starbug genunix: [ID 540533 kern.notice] SunOS Release 5.10 ...
Jan  3 08:44:41 starbug genunix: [ID 913631 kern.notice] Copyright 1983-2003 ...
Jan  3 08:44:41 starbug genunix: [ID 678236] Ethernet address ...
Jan  3 08:44:41 starbug unix: [ID 389951] mem = 131072K (0x8000000)
Jan  3 08:44:41 starbug unix: [ID 930857] avail mem = 121888768
Jan  3 08:44:41 starbug rootnex: [ID 466748] root nexus = Sun Ultra 5/
10 UPA/PCI (UltraSPARC-IIi 333MHz)
Jan  3 08:44:41 starbug rootnex: [ID 349649] pcipsy0 at root: UPA 0x1f0x0
Jan  3 08:44:41 starbug genunix: [ID 936769] pcipsy0 is /pci@1f,0
Jan  3 08:44:41 starbug pcipsy: [ID 370704] PCI-device: pci@1,1, simba0
Jan  3 08:44:41 starbug genunix: [ID 936769] simba0 is /pci@1f,0/pci@1,1
Jan  3 08:44:41 starbug pcipsy: [ID 370704] PCI-device: pci@1, simba1
Jan  3 08:44:41 starbug genunix: [ID 936769] simba1 is /pci@1f,0/pci@1
Jan  3 08:44:57 starbug simba: [ID 370704] PCI-device: ide@3, uata0
Jan  3 08:44:57 starbug genunix: [ID 936769] uata0 is /pci@1f,0/pci@1,
Jan  3 08:44:57 starbug uata: [ID 114370] dad0 at pci1095,6460

See Also

For more information, see the dmesg(1M) man page.