topic Re: What's the point of /var/adm/messages on HPUX? in Operating System - HP-UX

What's the point of /var/adm/messages on HPUX?

Bart_6 — Wed, 14 Jan 2004 04:17:56 GMT

What's the point of /var/adm/messages and dmesg on HPUX when you have the syslog containing the information you want?

Re: What's the point of /var/adm/messages on HPUX?

Umapathy S — Wed, 14 Jan 2004 04:37:30 GMT

I have never seen messages and dmesg on hpux. Can I know which product/fileset contains these two. As far as I know syslog.log is the main log in hpux.

Umapathy

Re: What's the point of /var/adm/messages on HPUX?

Sunil Sharma_1 — Wed, 14 Jan 2004 04:42:20 GMT

Hi,

dmesg is work before syslogd start becoz syslog starts at run level 2.

not sure about /var/adm/messages (in my system 10.20 this file is not there even).

Sunil

Re: What's the point of /var/adm/messages on HPUX?

Michael Tully — Wed, 14 Jan 2004 04:44:01 GMT

dmesg prints the current buffer
/var/adm/messages is NOT the default messages file on HPUX.
/var/adm/syslog/syslog.log is.
To tell have a look at /etc/syslog.conf file which defines what is captured and to where.

Re: What's the point of /var/adm/messages on HPUX?

Robert-Jan Goossens — Wed, 14 Jan 2004 04:47:05 GMT

Hi Bart,

Could you check your root user crontab for the line

# /usr/sbin/dmesg - >> /var/adm/messages

If that is configured, dmesg will append the messages file.

Hope this helps,
Robert-Jan

Re: What's the point of /var/adm/messages on HPUX?

Bart_6 — Wed, 14 Jan 2004 04:47:41 GMT

As far I know the dmesg command is a unix default.
Is it correct in assuming that output generated by dmesg also appears in the syslog (as configured in the /etc/syslog.conf). So the dmesg command is virtually useless?

Re: What's the point of /var/adm/messages on HPUX?

Bart_6 — Wed, 14 Jan 2004 04:49:52 GMT

In other words....

There's no need to maintain a /var/adm/messages file and there is no reason to use the dmesg command if you have your syslog configured correctly?

Re: What's the point of /var/adm/messages on HPUX?

John Carr_2 — Wed, 14 Jan 2004 04:56:01 GMT

dmesg command is very useful you can issue it from any where saving having to change directory to read output file. The fact that it computes incrementally means you only display messages since you last executed the command ie only the ones you really want to read. The messages file is created through the output of dmesg vcheck cron. A full explanation of this can be attained by man dmesg.

:-) John.

Re: What's the point of /var/adm/messages on HPUX?

Robert-Jan Goossens — Wed, 14 Jan 2004 04:56:37 GMT

Hi again,

Yes the messages reported by dmesg will also be written to the syslog file. No dmesg is not an unusefull command because it will report on demand specific system errors, while syslog reports all kind off errors (login, ftp etc).

Dmesg is usefull when there is a sudden problem, if you need to search the syslog file it will take more time.

Regards,
Robert-Jan

Re: What's the point of /var/adm/messages on HPUX?

Alex Glennie — Wed, 14 Jan 2004 04:56:39 GMT

As to the var/adm/messages file .... anything in your crontab file to explain it ?

Re: What's the point of /var/adm/messages on HPUX?

Bart_6 — Wed, 14 Jan 2004 04:59:35 GMT

The crontab has indeed the dmesg entry.
I'm irged to delete it because it has nu direct use....

Re: What's the point of /var/adm/messages on HPUX?

Robert-Jan Goossens — Wed, 14 Jan 2004 05:02:16 GMT

PS,

I have setup the messages file too, we are running as mixed system env ( solaris, aix and hpux ) admins tend to search the messages file if there is a panic situation. (:-)

Robert-Jan

Re: What's the point of /var/adm/messages on HPUX?

Fabio Ettore — Wed, 14 Jan 2004 05:04:06 GMT

Hi,

I know that /var/adm/messages is on Tru64, it is the equivalent of syslog.log of HP-UX.
Instead dmesg is a quick command for diagnostic messages and form error log, it usually reports messages that syslog.log contains too.

I hope this helps you.

Best regards,
Ettore

Re: What's the point of /var/adm/messages on HPUX?

John Carr_2 — Wed, 14 Jan 2004 05:04:52 GMT

Bart

you may think its of no use to you but another sys admin working in your absense having to deal with a problem may like to have this. Is there really anything to be gained by removing the service ?

:-) John.

Re: What's the point of /var/adm/messages on HPUX?

Jakes Louw — Wed, 14 Jan 2004 06:36:24 GMT

AFAIAC, dmesg is a good supplemental diagnostic tool with Syslogger and STM.
The only drawback is that it works with a buffer, and that is the reason for the redirection from crontab using the "dmesg -" incremental switch to display only messages since the last call.

I have had cases where I've picked up problems (especially H/W) quicker from a remsh call to dmesg than from trying to filter out what's useful in the syslog.

Re: What's the point of /var/adm/messages on HPUX?

Pete Randall — Wed, 14 Jan 2004 06:55:06 GMT

Take a look at the man page for dmesg for an explanation of the /var/adm/messages file:

If the - argument is
specified, dmesg computes (incrementally) the new messages since the
last time it was run and places these on the standard output. This is
typically used with cron (see cron(1)) to produce the error log
/var/adm/messages by running the command:

/usr/sbin/dmesg - >> /var/adm/messages

every 10 minutes.

Pete

Re: What's the point of /var/adm/messages on HPUX?

Cheryl Griffin — Wed, 14 Jan 2004 08:36:59 GMT

/var/adm/messages is a old cross-platform unix standard which we've gotten a bit away from since we use dmesg and syslog. Some unix die-hards want it, some don't.

Check out which platforms use it at the Rosetta Stone. http://bhami.com/rosetta.html