sysdef and kmtune

[sudheer_7]

Hi,

I have a 11.11 server. When I want to view the value of a kernel parameter, which is being currently used, I check with sysdef and kmtune -l. But the output differs.

I was checking value of nbuf. sysdef shows a value of some 28000 plus and kmtune -l -q nbuf shows 0.

Which is the correct value please..? And which command should I use?

Sudheer

[James R. Ferguson]

Hi Sudheer:

Beginnimg with 11.0 'kmtune' should be used in preference to 'sysdef' which is deprecated.

In 11.23, 'kmtune' is deprecated and replaced by 'kctune'.

Thus, for 11.11, you should use 'kmtune' to query and/or set kernel parameters.

The manpages offer additional information.

Regards!

...JRF...

[JIJ_1]

Hi Sudheer,

You can use kmtune or SAM utility to get the accurate value.

JIJ

[Bill Hassell · Accepted solution]

nbuf and bufpages will have a value with sysdef because it is reading an in-core values that are constantly changing. When the kernel is built, the values shown by kmtune (kctune for 11.23) are used to build the kernel. When nbuf and bufpages are both zero (from kmtune) then the size of the buffer cache is defined by the dynamic buffer cache percentages: dbc_max_pct and dbc_min_pct. Forget sysdef as it is obsolete and will be removed in future versions of HP-UX.

[inventsekar_1]

use kmtune for 11.11 and kctune for 11.23

in 11.23, u can also use kcweb- web interface for kernel configuration. Alarams, graphical representation of tunable values, new dynamic tunnables...etc... 11.23 kernel configuration is fun.

[Raj D.]

Sudheer,

You can use the following :

# glance -t

# sar -v


Cheers,
Raj.

[Raj D.]

Sudheer,

You can use the following :

# glance -t

# sar -v 5 5


Cheers,
Raj.

[Lethuillier]

"sysdef" command checks the currently running system (kernel) and reports its tunable configuration parameters.
It may be different from /stand/system, if someone edited /stand/system and hasn't rebuilt the kernel since then.

"kmtune" command takes the kernel parameter value from /stand/system.

That's why "sysdef" and "kmtune" don't display the same output.

In order to display the differences between "Current" & "Planned" kernel values, go into SAM -> kernel configuration, the "Current" & "Pending" values are different from "kmtune".

To see what SAM is doing is to execute /usr/sam/bin/samlog_viewer -l C /var/sam/log/samlog.

This will open a window which extracts the commands executed by SAM.

[sudheer_7]

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