kernel parameters

[Troyan Krastev]

Hi all,

I have to install IBM MQ Series on two of my boxes. I installation guide I see SEMMNU=2048. That works for HP-UX10.20, but when I try to change it for HP-UX11 it give me the message:
Error: One or more tunable parameters violates an interdependency rule. SAM expects the following expression(s) to be true: semmnu <= (nproc-4)
Can I avoid limitation of the formula for this parameter?
Applied Kernel Parameter Set is General OLTP/Database Server System.

Thanks,
Troy.

[Joseph C. Denman]

Not sure if you can. However, I would not suggest trying. I would up the nproc parm to 4 more then semmnu.

...jcd...

[Thierry Poels_1 · Accepted solution]

hi,
I agree with Joseph : increase you nproc parameter first.
BTW nproc < 2000 is rather low for a database server.
regards,
Thierry.

[Praveen Bezawada]

Hi
I think you can override the formula limitation if you set it from command line( i am not 100% sure ) though I suggest you not to.
Anyway the commands for changing the values from command line are

kmtune -s semmnu=2048
mk_kernel -v -o /stand/vmunix

Then reboot the machine.

Hope this helps...

...BPK...

[Troyan Krastev]

Hi Thierry,

Some calculations:
semmnu=nproc-4
nproc=(((10*MAXUSERS)/3)+128)
If I want semmnu=2048 then MAXUSERS=574, but when I try to change MAXUSERS I get:
The parameter modification(s) you have made have resulted in at least
one parameter evaluating to a value which is greater than its maximum
allowable value. Parameter "msgseg", currently set to "(MSGTQL*4)",
has evaluated to "71440", which is greater than its maximum allowable
value of "32767".

[nancy rippey]

I am running MQSeries on two HP servers running 11.0. The kernel parameters are set as follows and things are working just fine.
STRMSGSZ 65535
max_thread_proc 256
maxfiles 2048
maxfiles_lim 2048
maxswapchunks 700
maxuprc 300
maxusers 300
msgmax 65536
msgmnb 65536
msgmni 350
msgseg 7168
msgssz 1024
msgtql 1024
ncallout 3000
nkthread 2048
nstrpty 60
o_sync_is_o_dsync 1
semaem 32767
semmni 4980
semmns 16384
semmnu 2048
semume 256
semvmx 65535
shmmni 1024
shmseg 1024

[nancy rippey]

Use the semaphone settings I sent earlier. Change semmns semmni first and then you will be able to go 2048 on semmnu

[Magdi KAMAL]

Hi Troy.,

1. You may increase your nproc to a greator value ( 2068 for example ).

OR

2. You may modify the formula :
semmnu <= (nproc-4)
by
semmnu <= (nproc-4 + 1500)


Magdi

[Troyan Krastev]

Hi Maqdi,

:-), this is exactly what I am trying to do! How to do it?

[Thierry Poels_1]

hi,
increasing MAXUSERS has an effect on serveral kernel settings which might or might not be relevant for your system.
Personally I would increase nproc (fix number instead of formula) and semmnu.
(next to kmtune you can always use sam to modify the kernel parameters.)

good luck,
Thierry.