DMESG question

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DMESG question

Gabriel George POPA
I have two small questions:
1) When the OS generates too much messages, old messages are lost
(oldest lines present in `dmesg` are lost).
What can I do to see ALL messages ever recorded for dmesg printing? More
precisely, take a look at my `dmesg`:
# dmesg
arp info overwritten for 193.231.39.129 by 00:90:bf:10:88:40 on vr0
arp info overwritten for 193.231.39.129 by 00:10:dc:4c:6f:6c on vr0
arp info overwritten for 193.231.39.36 by 00:15:f2:16:f8:b4 on vr0
arp info overwritten for 193.231.39.54 by 00:e0:29:9b:bc:6c on vr0
...
(and a lot of other similar messages, similar if not even identical)

Most questions on this mail list require me to provide a valid output of
dmesg. But if old messages are erased, how am I
supposed to do this? I am not allowed to reboot the machine! The machine
is supposed to be running 24/7, NO reboot allowed.

2) What do these lines mean (the lines I copied above from the output of
`dmesg`)?

NOTE: I'm using OpenBSD 3.8 on i386 (P4).

                                                                                                                                                   
Yours in BSDness,
                                                                                                                                                             
Gabriel George POPA

Loz
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Re: DMESG question

Loz
Gabriel,

You can always pipe it to more, like this

# dmesg | more

and you can make the output go to a file, with

# dmesg > filename

Regards,

Loz

On 8/7/06, Gabriel George POPA <[hidden email]> wrote:

>
> I have two small questions:
> 1) When the OS generates too much messages, old messages are lost
> (oldest lines present in `dmesg` are lost).
> What can I do to see ALL messages ever recorded for dmesg printing? More
> precisely, take a look at my `dmesg`:
> # dmesg
> arp info overwritten for 193.231.39.129 by 00:90:bf:10:88:40 on vr0
> arp info overwritten for 193.231.39.129 by 00:10:dc:4c:6f:6c on vr0
> arp info overwritten for 193.231.39.36 by 00:15:f2:16:f8:b4 on vr0
> arp info overwritten for 193.231.39.54 by 00:e0:29:9b:bc:6c on vr0
> ...
> (and a lot of other similar messages, similar if not even identical)
>
> Most questions on this mail list require me to provide a valid output of
> dmesg. But if old messages are erased, how am I
> supposed to do this? I am not allowed to reboot the machine! The machine
> is supposed to be running 24/7, NO reboot allowed.
>
> 2) What do these lines mean (the lines I copied above from the output of
> `dmesg`)?
>
> NOTE: I'm using OpenBSD 3.8 on i386 (P4).
>
>
> Yours in BSDness,
>
> Gabriel George POPA

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Re: DMESG question

Landry Breuil
> On 8/7/06, Gabriel George POPA <[hidden email]> wrote:
>> I have two small questions:
>> 1) When the OS generates too much messages, old messages are lost
>> (oldest lines present in `dmesg` are lost).
>> What can I do to see ALL messages ever recorded for dmesg printing?

There is always a copy of the original dmesg in /var/run/dmesg.boot

Landry

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Re: DMESG question

Stuart Henderson
In reply to this post by Gabriel George POPA
On 2006/08/07 16:15, Gabriel George POPA wrote:
> 1) When the OS generates too much messages, old messages are lost
> (oldest lines present in `dmesg` are lost).
> What can I do to see ALL messages ever recorded for dmesg printing? More
> precisely, take a look at my `dmesg`:

/var/log/messages if they're not rotated too far away
(change newsyslog.conf if you want to keep them for longer).

> # dmesg
> arp info overwritten for 193.231.39.129 by 00:90:bf:10:88:40 on vr0
> arp info overwritten for 193.231.39.129 by 00:10:dc:4c:6f:6c on vr0
> arp info overwritten for 193.231.39.36 by 00:15:f2:16:f8:b4 on vr0
> arp info overwritten for 193.231.39.54 by 00:e0:29:9b:bc:6c on vr0

this is IP addresses moving between machines.

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Re: DMESG question

Steffen Wendzel
In reply to this post by Gabriel George POPA
Hi Gabriel,

old versions of /var/log/messages are stored in a gzip compressed
form in /var/log too and are called messages.<number>.gz

steffen

--
http://cdp.doomed-reality.org

why the 'never ending story' makes the
'mission impossible' in /bin/sh:

   while [ 1 ]; do sleep 1; done; do_mission;

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Re: DMESG question

Gabriel George POPA
In reply to this post by Stuart Henderson
            Thank you, that's what I was looking for :)

                                   


Stuart Henderson wrote:

>On 2006/08/07 16:15, Gabriel George POPA wrote:
>  
>
>>1) When the OS generates too much messages, old messages are lost
>>(oldest lines present in `dmesg` are lost).
>>What can I do to see ALL messages ever recorded for dmesg printing? More
>>precisely, take a look at my `dmesg`:
>>    
>>
>
>/var/log/messages if they're not rotated too far away
>(change newsyslog.conf if you want to keep them for longer).
>
>  
>
>># dmesg
>>arp info overwritten for 193.231.39.129 by 00:90:bf:10:88:40 on vr0
>>arp info overwritten for 193.231.39.129 by 00:10:dc:4c:6f:6c on vr0
>>arp info overwritten for 193.231.39.36 by 00:15:f2:16:f8:b4 on vr0
>>arp info overwritten for 193.231.39.54 by 00:e0:29:9b:bc:6c on vr0
>>    
>>
>
>this is IP addresses moving between machines.

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Re: DMESG question

Gabriel George POPA
In reply to this post by Landry Breuil
All right, even better. Thank you all.

                               Yours in BSDness,
                                           George


Landry wrote:

>> On 8/7/06, Gabriel George POPA <[hidden email]> wrote:
>>
>>> I have two small questions:
>>> 1) When the OS generates too much messages, old messages are lost
>>> (oldest lines present in `dmesg` are lost).
>>> What can I do to see ALL messages ever recorded for dmesg printing?
>>
>
> There is always a copy of the original dmesg in /var/run/dmesg.boot
>
> Landry

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Re: DMESG question

daniel.ramaley (Bugzilla)
In reply to this post by Gabriel George POPA
On Monday 07 August 2006 08:15, Gabriel George POPA wrote:
>Most questions on this mail list require me to provide a valid output
> of dmesg. But if old messages are erased, how am I
>supposed to do this?

Take a look at /var/run/dmesg.boot.

------------------------------------------------------------------------
Dan Ramaley                            Dial Center 118, Drake University
Network Programmer/Analyst             2407 Carpenter Ave
+1 515 271-4540                        Des Moines IA 50311 USA

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Re: DMESG question

Alexander Hall
In reply to this post by Gabriel George POPA
Gabriel George POPA wrote:
> I have two small questions:
> 1) When the OS generates too much messages, old messages are lost
> (oldest lines present in `dmesg` are lost).

`dmesg' displays the system message buffer, which has a limited space.
Therefore, when it is full, it starts overwriting itself. Thus, lost
messages are indeed lost.

> What can I do to see ALL messages ever recorded for dmesg printing?

You could write some script that `dmesg > /some/where/$time`
periodically (cron job).

> More precisely, take a look at my `dmesg`:
> # dmesg
> arp info overwritten for 193.231.39.129 by 00:90:bf:10:88:40 on vr0
> arp info overwritten for 193.231.39.129 by 00:10:dc:4c:6f:6c on vr0
> arp info overwritten for 193.231.39.36 by 00:15:f2:16:f8:b4 on vr0
> arp info overwritten for 193.231.39.54 by 00:e0:29:9b:bc:6c on vr0
> ...
> (and a lot of other similar messages, similar if not even identical)
>
> Most questions on this mail list require me to provide a valid output of
> dmesg. But if old messages are erased, how am I
> supposed to do this?

$ cat /var/run/dmesg.boot

> I am not allowed to reboot the machine! The machine
> is supposed to be running 24/7, NO reboot allowed.

Isn't this machine ever upgraded? Or, if it is so important - what about
redundancy? Well well.

> 2) What do these lines mean (the lines I copied above from the output of
> `dmesg`)?

I'd say some machines are fighting over the same ip address. I could be
wrong, though. Don know, but I get a feeling that some failover
solution(s) could cause this.

/Alexander

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Re: DMESG question

Jiri Belka
In reply to this post by Gabriel George POPA
Cituji Gabriel George POPA <[hidden email]>:

> I have two small questions:
> 1) When the OS generates too much messages, old messages are lost
> (oldest lines present in `dmesg` are lost).
> What can I do to see ALL messages ever recorded for dmesg printing?
> More precisely, take a look at my `dmesg`:
> # dmesg
> arp info overwritten for 193.231.39.129 by 00:90:bf:10:88:40 on vr0
> arp info overwritten for 193.231.39.129 by 00:10:dc:4c:6f:6c on vr0
> arp info overwritten for 193.231.39.36 by 00:15:f2:16:f8:b4 on vr0
> arp info overwritten for 193.231.39.54 by 00:e0:29:9b:bc:6c on vr0
> ...
> (and a lot of other similar messages, similar if not even identical)

man arp(4) -  
http://www.openbsd.org/cgi-bin/man.cgi?query=arp&apropos=0&sektion=0&manpath=OpenBSD+Current&arch=i386&format=html#end

jirib

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Re: DMESG question

Nick Holland
In reply to this post by Stuart Henderson
Stuart Henderson wrote:
> On 2006/08/07 16:15, Gabriel George POPA wrote:
>> 1) When the OS generates too much messages, old messages are lost
>> (oldest lines present in `dmesg` are lost).
>> What can I do to see ALL messages ever recorded for dmesg printing? More
>> precisely, take a look at my `dmesg`:
>
> /var/log/messages if they're not rotated too far away
> (change newsyslog.conf if you want to keep them for longer).

PLEASE, NO.  Bad advice.

Either use the dmesg command or the /var/run/dmesg.boot  DO NOT pull
your dmesg out of messages if you are seriously expecting help from
others.  If for some reason messages is your only option, carefully edit
out the date and time stuff before posting.  If you just paste in your
messages output raw, I'm unlikely to spend much time looking at your
query.  Some people may...but not me.

Which would you rather dig through looking for the one little gem that
explains a problem?

This:
Jul 24 09:03:27 njh-9 /bsd: OpenBSD 3.9-current (GENERIC) #922: Wed Jun
28 23:06
:50 MDT 2006
Jul 24 09:03:27 njh-9 /bsd:
[hidden email]:/usr/src/sys/arch/i386/
compile/GENERIC
Jul 24 09:03:27 njh-9 /bsd: cpu0: Intel(R) Pentium(R) 4 CPU 1300MHz
("GenuineInt
el" 686-class) 1.30 GHz
Jul 24 09:03:27 njh-9 /bsd: cpu0:
FPU,V86,DE,PSE,TSC,MSR,PAE,MCE,CX8,SEP,MTRR,PG
E,MCA,CMOV,PAT,PSE36,CFLUSH,DS,ACPI,MMX,FXSR,SSE,SSE2,SS,HTT,TM
Jul 24 09:03:27 njh-9 /bsd: real mem  = 133296128 (130172K)
Jul 24 09:03:27 njh-9 /bsd: avail mem = 114892800 (112200K)
Jul 24 09:03:27 njh-9 /bsd: using 1652 buffers containing 6766592 bytes
(6608K)
of memory
Jul 24 09:03:27 njh-9 /bsd: mainbus0 (root)
Jul 24 09:03:27 njh-9 /bsd: bios0 at mainbus0: AT/286+(00) BIOS, date
11/30/00,
BIOS32 rev. 0 @ 0xffe90, SMBIOS rev. 2.3 @ 0xf0450 (97 entries)
Jul 24 09:03:27 njh-9 /bsd: bios0: Dell Computer Corporation Dimension 8100
  ...

or this:
OpenBSD 3.9-current (GENERIC) #922: Wed Jun 28 23:06:50 MDT 2006
     [hidden email]:/usr/src/sys/arch/i386/compile/GENERIC
cpu0: Intel(R) Pentium(R) 4 CPU 1300MHz ("GenuineIntel" 686-class) 1.30 GHz
cpu0:
FPU,V86,DE,PSE,TSC,MSR,PAE,MCE,CX8,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CFLUSH,
DS,ACPI,MMX,FXSR,SSE,SSE2,SS,HTT,TM
real mem  = 133296128 (130172K)
avail mem = 114892800 (112200K)
using 1652 buffers containing 6766592 bytes (6608K) of memory
mainbus0 (root)
bios0 at mainbus0: AT/286+(00) BIOS, date 11/30/00, BIOS32 rev. 0 @
0xffe90, SMB
IOS rev. 2.3 @ 0xf0450 (97 entries)
bios0: Dell Computer Corporation Dimension 8100
  ,,,

All the date and time crap doesn't add anything for us, it just makes it
completely unreadable, at least to me.

If you want our help on something, MAKE IT EASY FOR US.  Note how ugly
that all looks, I was (intentionally) completely careless with the line
wraps, and it STILL looks a lot better than some of the crap you guys
post to the lists.

But watch this: If I use my mail client smartly:

> OpenBSD 3.9-current (GENERIC) #922: Wed Jun 28 23:06:50 MDT 2006
>     [hidden email]:/usr/src/sys/arch/i386/compile/GENERIC
> cpu0: Intel(R) Pentium(R) 4 CPU 1300MHz ("GenuineIntel" 686-class) 1.30 GHz
> cpu0: FPU,V86,DE,PSE,TSC,MSR,PAE,MCE,CX8,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CFLUSH,DS,ACPI,MMX,FXSR,SSE,SSE2,SS,HTT,TM
> real mem  = 133296128 (130172K)
> avail mem = 114892800 (112200K)
> using 1652 buffers containing 6766592 bytes (6608K) of memory
> mainbus0 (root)
> bios0 at mainbus0: AT/286+(00) BIOS, date 11/30/00, BIOS32 rev. 0 @ 0xffe90, SMB
> IOS rev. 2.3 @ 0xf0450 (97 entries)
> bios0: Dell Computer Corporation Dimension 8100
   ...
wow...so much more readable (assuming I didn't really snip my dmesg, of
course).  Yes, it took at least ten seconds longer to do that than it
did to stupidly copy/paste, but I can assure you, I'd spend a lot more
time reading it without stupid wrapping.

Nick.