topic Re: root commands hangs in Operating System - HP-UX

root commands hangs

subhuti — Fri, 13 Aug 2010 06:18:31 GMT

Hi there
I have an old HP-UX 11.11

and I got problem with it yesterday
my users said that they can't access server via ssh

I'm getting this
ssh_exchange_identification: Connection closed by remote host

but I able to login with telnet , and can issue any commands under my user and when I became root I can't run any command
all commands hangs

nothing interesting in the logs:(

Re: root commands hangs

Dennis Handly — Fri, 13 Aug 2010 06:20:47 GMT

>when I became root I can't run any command

How do you become root? su or su -?

Re: root commands hangs

subhuti — Fri, 13 Aug 2010 06:54:51 GMT

Oh thanks for this reply
I've tried just "su -"

not I become root with "su"
and all good

probably something happens with ~/.profile

Re: root commands hangs

Elmar P. Kolkman — Fri, 13 Aug 2010 06:57:19 GMT

When the process table is filled-up or you are out of memory, something like this can happen.

Telnet is lightweight compared to ssh.

Can you run single commands with 'sudo' or 'su root -c'?
For instance:
$ sudo ls

or
$ su root -c "/usr/bin/ls"

Re: root commands hangs

Elmar P. Kolkman — Fri, 13 Aug 2010 06:58:42 GMT

Check out /var/spool/mail and your wtmp file.
In the default .profiles, a check is performed to see when you last logged in and if you have new E-mail.

Re: root commands hangs

Dennis Handly — Fri, 13 Aug 2010 06:59:27 GMT

>probably something happens with ~/.profile

Yes. You can add "set -x" to trace your execution.

Re: root commands hangs

Kapil Jha — Fri, 13 Aug 2010 07:02:43 GMT

can you run top/glance/swapinfo or all the commands are hanging.
If nothing is working from other users as well they probably you may have to reboot.

BR,
Kapil+

Re: root commands hangs

subhuti — Fri, 13 Aug 2010 07:21:31 GMT

thanks guys
all good with system ( memory, CPU, process table)

root cause of ssh problem probably was in
MaxStartups option
ps -ef | grep ssh shows me 11 processes but
this option has just 10
I've increased it to 20 , send HUP signal to ssh daemon... and now I have not any problems

Re: root commands hangs

subhuti — Fri, 13 Aug 2010 10:37:16 GMT

found interesting thing

root had in profile this

export PATH=/opt/lib/cobol/bin:$PATH

with this string I can't issue commands

I've fixed this with:

export PATH=$PATH:/opt/lib/cobol/bin
....
but
I have another one string in ~/.profile:
export PATH=/tuxedo/tuxedo8.0/bmrs/lib:$PATH

and I have not any problems with it...

PS
don't know how it worked earlier

Re: root commands hangs

subhuti — Fri, 13 Aug 2010 11:16:21 GMT

heh
nice, /opt/ located on the external disk (Fiber Channel)
and this disk is unavailable ... (ls /opt/ hangs)

Re: root commands hangs

Viktor Balogh — Sat, 14 Aug 2010 17:36:43 GMT

>>export PATH=/opt/lib/cobol/bin:$PATH

>nice, /opt/ located on the external disk (Fiber Channel)
and this disk is unavailable ... (ls /opt/ hangs)

it explains your problems with hanging commands: according to the old PATH variable, /opt/lib/cobol/bin was searched first at every command...