topic Re: /stand/vmunix missing. in Operating System - HP-UX

/stand/vmunix missing.

Vinoyee Madashery Poulo — Thu, 26 Feb 2009 08:08:38 GMT

We have installed inode patches on one of the HP-UX 11.31 server and rebooted box one and half months ago. After some time we found that /stand/vmunix is missing. However, the /stand/current/vmunix has the time stamp for the day we rebuilt the kernel. The adb command returns /stand/vmunix.

# echo boot_string/s | adb /stand/current/vmunix /dev/kmem

boot_string:

(;)/stand/vmunix

We have checked other 11.31 server and found that /stand/vmuinx is the hard link to /stand/current/vmunix

I am not denying the possibility that some one would have accidentally removed /stand/vmunix.

Could some one help what whould have happened in this case? Is there any way to make sure from which kernel the system is rebooted?
Did any one face similar issue? Also please let us know, if /stand/vmunix is hard link to /stand/current/vmunix or vice versa.

Points will be given promptley.

Re: /stand/vmunix missing.

Sameer Kelkar — Thu, 26 Feb 2009 08:21:51 GMT

have you checked
#kclog

All kernel changes are recordrd in /var/adm/kc.log.

Re: /stand/vmunix missing.

Venkatesh BL — Thu, 26 Feb 2009 08:53:27 GMT

On my 11.31, /stand/vmunix is a hardlink of /stand/current/vmunix.

Re: /stand/vmunix missing.

Duncan Edmonstone — Thu, 26 Feb 2009 09:03:56 GMT

>> Is there any way to make sure from which kernel the system is rebooted?

You already did this:

># echo boot_string/s | >adb /stand/current/vmunix /dev/kmem
>
>boot_string:
>
>(;)/stand/vmunix

That's what the in-core kernel booted from.

So someone or something removed the hard link to /stand/current/vmunix

HTH

Duncan

Re: /stand/vmunix missing.

Sameer Kelkar — Thu, 26 Feb 2009 09:05:21 GMT

Hello
Since /stand/vmunix is missing & if u r feeling unsafe for reboot, You can save a copy of running configuration by :
#kconfig -s confname

also #kcpath will give path of current kernel.
stand/vmunix is hard link to /stand/current/vmunix

Re: /stand/vmunix missing.

Venkatesh BL — Thu, 26 Feb 2009 09:19:16 GMT

# kcpath -d
/stand/current

;; Print the directory containing the currently running kernel

Re: /stand/vmunix missing.

Vinoyee Madashery Poulo — Thu, 26 Feb 2009 09:29:16 GMT

Thanks for the replies and I have assigned the points.

Venkatesh, the kcpath -d output is as follows.

# kcpath -d
/stand/current

Does this mean, the system booted using /stand/current/vmunix?

In that case /stand/vmunix should be the hard link to /stand/current/vmunix.

The /stand/vmunix and /stand/current/vmunix will have same time stamp and inode number.
The /stand/system is soft link to /stand/current/system.
Hence, I think /stand/current/vmunix should he hard linked to /stand/vmunix.

Re: /stand/vmunix missing.

Duncan Edmonstone — Thu, 26 Feb 2009 09:39:15 GMT

Even stranger...

On my system /stand/system is a symbolic link to /stand/nextboot/system (which I'm pretty sure is correct)

I think at this point I'd be having an interesting disucssion with everyone who has root privilges on this system...

HTH

Duncan

Re: /stand/vmunix missing.

Vinoyee Madashery Poulo — Fri, 27 Feb 2009 05:37:51 GMT

Duncan,

lrwxr-xr-x 1 root root 15 Jan 23 22:54 system -> nextboot/system
lrwxr-xr-x 1 root sys 7 Feb 9 10:38 nextboot -> current
drwxr-xr-x 5 root sys 8192 Jan 23 22:54 current
# cd current
# ls -l
total 265760
-rw-r--r-- 1 root root 525972 Jan 23 22:54 .cache
-rw-r--r-- 1 root sys 0 Jan 23 22:34 .config
-rw-r--r-- 1 root sys 147 Jan 23 22:34 README
drwxr-xr-x 3 root sys 96 Jan 23 22:34 bootfs
drwxr-xr-x 2 root sys 96 Jan 23 22:34 krs
-rw-r--r-- 1 root sys 6027 Jan 23 22:34 ldargs
drwxr-xr-x 2 root sys 8192 Jan 23 22:34 mod
-rw-r--r-- 1 root sys 5044 Feb 9 10:38 system
-rwxr-xr-x 2 root sys 135496680 Jan 23 22:34 vmunix

# pwd
/stand

ls -il nextboot/system
51 -rw-r--r-- 1 root sys 5044 Feb 9 10:38 nextboot/system

# cd current
# ls -il system
51 -rw-r--r-- 1 root sys 5044 Feb 9 10:38 system

So, /stand/system is a soft link to /stand/current/system.

Could any one please answer if the /stand/vmunix hard linked to /stand/current/vmunix or vice versa?

Re: /stand/vmunix missing.

Duncan Edmonstone — Fri, 27 Feb 2009 07:47:59 GMT

Yes /stand/vmunix is a hard link to /stand/current/vmunix.

It would be interesting to see what "kconfig -w" says so you can see where this kernel configuration came from...

HTH

Duncan

Re: /stand/vmunix missing.

VK2COT — Fri, 27 Feb 2009 10:16:08 GMT

Hello,

Are there any deferred changes in the kernel:

kconfig -D

In fact, are there any deferred changes for
modules and parameters too:

kctune -D
kcmodule -D

Did you check the kernel changes via
kclog(1M) command (or simply check
/var/adm/kc.log).

I have seen some very weird errors (mostly
caused by humans) in my time. That is why,
whenever I am called to audit servers, or
run projects, I run my own Perl script:

http://www.circlingcycle.com.au/Unix-sources/HP-UX-check-OAT.pl.txt

Close to 600 tests are performed :) So
far, I did not fail me, but your mileage
might be different.

Cheers,

VK2COT

Re: /stand/vmunix missing.

Vinoyee Madashery Poulo — Mon, 02 Mar 2009 11:07:17 GMT

Hi all,

We have rebooted the box and it created /stand/vmunix. So it is clear that /stand/vmunix is hard linked to /stand/current/vmunix. Special thanks to one and all who responded to this thread.

Re: /stand/vmunix missing.

Vinoyee Madashery Poulo — Mon, 02 Mar 2009 11:12:06 GMT

As the issue resolved. I am closing the thread.

Re: /stand/vmunix missing.

Vinoyee Madashery Poulo — Mon, 02 Mar 2009 11:15:24 GMT

Issue resolved