topic Re: Kernel tunning won't work in Operating System - HP-UX

Kernel tunning won't work

Tingli — Thu, 13 Sep 2007 11:15:20 GMT

The system is rp3440 with hp-ux 11.23. When I tried to modify kernel parameter nproc I got the message as:

# # kctune nproc=4096
ERROR: The value 163840 is outside the range of valid values (min=1
max=32767) for the tunable msgseg

I don't see there is any relations between msgseg yet it won't allow me to modify nproc.

Over here, nproc is a dynamic one while msgseg is a static one.

Re: Kernel tunning won't work

A. Clay Stephenson — Thu, 13 Sep 2007 11:31:47 GMT

You may be dealing with an artifact of an earlier attempt to modify the kernel. Have a look at your current system file and check the value for msgseg. Someone may have "cowboy" directly edited the file.

You should also check to see if your kctune patches are current. PHCO_34195 is the most recent.

Re: Kernel tunning won't work

Tim Nelson — Thu, 13 Sep 2007 12:36:23 GMT

Correct the error in the msgseg and then set nproc.

review current kernel with what is in /stand/system.. As noted there was a change made outside of using kctune.

Re: Kernel tunning won't work

Tingli — Thu, 13 Sep 2007 12:57:04 GMT

Found out the cause of the error.

Actually, the setting in kctune is:
Tunable Value Expression
.
.
.
msgseg 26560 (msgtql*4)
msgtql 6640 (nproc*10)
.
.
.
nproc 664 (((200)*3)+64)

That is why msgseg is out of its range.

Re: Kernel tunning won't work

Tim Nelson — Thu, 13 Sep 2007 13:00:56 GMT

I have notice with 11.23 and new 11.31 that the defaults and the recommendation of other is not to use formulas in the kernel parameters.

This is probably a good example of why.