server hanging

[karthik_in83]

what are the steps we have to take when the server system hangs?If the application hangs,what are the steps?, If i am using anyone database.

[Dennis Handly]

If an application hangs, you debug it with gdb.
You can try attaching:
$ gdb executable PID-number

Or send a SIGQUIT so you can get a core file:
$ gdb executable core

[karthik_in83]

Hi dennis,

suppose if the application is very critical,i should not close that.will gdb command work?
Otherwise can we use nice or renice command to reduce the priority?

Then, can you tell me if the system hangs,what to do?
Suppose i should restart the pc.ok..i restarted.But now i want to know the causes. I can see /var/adm/syslog/syslog.log. Apart from that what we can check?

[karthik_in83]

Hi dennis,

suppose if the application is very critical,i should not close that.will gdb command work?
Otherwise can we use nice or renice command to reduce the priority?

Then, can you tell me if the system hangs,what to do?
Suppose i should restart the pc.ok..i restarted.But now i want to know the causes. I can see /var/adm/syslog/syslog.log. Apart from that what we can check?
by KK

[Dennis Handly]

>suppose if the application is very critical, i should not close that. will gdb command work?

Yes, after you are finished, you can detach and the process will continue.

>Otherwise can we use nice or renice command to reduce the priority?

Yes, you can also do "kill -STOP" and then "kill -CONT" on the process.

>can you tell me if the system hangs, what to do?

That requires taking a memory dump. Then you have to have HP analyze the problem.

>I can see /var/adm/syslog/syslog.log. Apart from that what we can check?

If the server hangs, I doubt there will be any info in any logs. That's what the crash dump is for.

[V. Nyga]

Hi,

'restart the pc' about what hardware do we speak?

If server hangs, check if you can rlogin.
Check processes with 'top' and memory usage (paging out?).

Also check lan - errors/collisions?

Volkmar

[karthik_in83]

hi,

can you tell me where the crash dump stored?
plz specify the path.........

by KK

hi nyga,

i am asking you after restart the pc,how do i find the cause of hanging......
how to check lan - errors/collisions?can you tell me?

by KK

[Dennis Handly]

>can you tell me where the crash dump stored?

/var/adm/crash/

To get a dump there the system has to crash, or you must press the TOC (Transfer Of Control) button, or execute the TC command on the MP.

>i am asking you after restart the PC

Calling an HP-UX server or workstation a PC is an insult. ;-)
And typically indicates a windows box. So please don't use that term in the HP-UX forum. (And don't use folder either.)

[karthik_in83]

thanks for your information dany

[V. Nyga]

Hi again,

can you give us some more infos, too?
What hardware? Which os?

Lan errors are stored also after reboot:

'landiag' - 'lan' - 'dis'
after hitting 'return' you get an 'Ethernet-like Statistics Group' where you can see 'FCS errors' and others.
These should be '0'. If not then you've a network problem, maybe lanspeed mismatch (FullDuplex versus HalfDuplex)

With 'q' you return to shell.

HTH
Volkmar