topic Re: Kernel tuning in Operating System - HP-UX

Kernel tuning

Dinesh_15 — Sat, 09 Apr 2005 01:06:36 GMT

Hi All

We are facing some problem in kernel tuning in
# model
9000/803/D220
# uname -a
HP-UX PLANT B.10.20 E 9000/803 2007679199 8-user license

We have seen following error in syslog file
Apr 4 16:59:31 PLANT telnetd[29911]: Cannot allocate pty
Apr 4 16:59:32 PLANT telnetd[29910]: Cannot allocate pty

As a remedy for this we have tried to increase the kernel parameter
nstrpty from 60 to 75 with following procedure.

#cd /stand/build
#rm *
#cp /stand/system /stand/syste.ori
#cp /stand/vmunix /stand/vmunix.ori
#/usr/lbin/sysadm/system_prep -s /stand/system
#vi /stand/system

Increase the value of parameter nstrpty from 60 75
#mk_kernel

But this will not build the kernel /stand/system_test

We tried using the options -s /stand/system .
It is not giving errors also, but generates two files. SAM kernel tuning also not working
Still it is giving problem.

Any ideas.

Rgds
Dinesh

Re: Kernel tuning

harry d brown jr — Sat, 09 Apr 2005 06:29:17 GMT

http://docs.hp.com/en/TKP-90202/re61.html

For all kernel parametera: http://docs.hp.com/en/TKP-90202/TKP-90202.pdf

live free or die
harry d brown jr

Re: Kernel tuning

Robert-Jan Goossens — Sat, 09 Apr 2005 09:53:15 GMT

Hallo Dinesh,

Check this thread.

http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=88126

Best regards,
Robert-Jan

Re: Kernel tuning

Bill Hassell — Sat, 09 Apr 2005 19:07:03 GMT

Changing the pty value always requires two steps: adjusting the kernel parameters (note: multiple parameters) and adding more device files. If you use SAM, all of this is handled automatically.

As a recommendation, don't increase from 60 to 75. Adding just 15 connections means you'll have to go through this process again when more logins are needed. I'd recommend increasing to at least 100. Every login, even from the same user requires an additional pty pair.

Also note that npty controls the old style pty driver. In 10.20, some connections will use the streams drivers so you need to change 3 values:

npty 100
nstrpty 100
nstrtel 100

Also, it looks like you've set the hostname PLANT using all UPPERCASE letters. This can cause network incompatibilities with other systems (Macs, PCs, etc).

Re: Kernel tuning

Dinesh_15 — Sun, 10 Apr 2005 03:09:56 GMT

Hi All

Thanks for the same.My problem is am not able build the kernel neither thru SAM nor thru command options. As said in the begining after increasing the value to 75 kernel is not buliding. There is no fail called vmunix.test i.e.rebiluded kernel.

Bill thanks for ur nice explanation.

Rgds
Dinsh

Re: Kernel tuning

Tim D Fulford — Sun, 10 Apr 2005 04:41:01 GMT

Hi

I could be wrong here but I do not like the fact you did rm * in /stand/build/. can you restore this dir & repeat what you did previously?

Regards

Tim

Re: Kernel tuning

radi_1 — Sun, 10 Apr 2005 08:44:59 GMT

Hi,
you need to edit /stand/build/system which was created by the system_prep command.
regards,

Re: Kernel tuning

Ermin Borovac — Sun, 10 Apr 2005 20:29:49 GMT

Can you post the output of

# sh -x /usr/sbin/mk_kernel