Easy points: kctune

[Adam Garsha]

If I want to change an immed tunable, say dbc_max_pct/dbc_min_pct, I believe I could do so like this:

kctune dbc_min_pct=1 dbc_max_pct=3

Will this also make the change saved in the config so that when I reboot it will be persistent?

How can I ensure that the change is activated immediately AND also is persistent across reboots? Maybe that one command does both, but it is not clear from the man pages.

[Hein van den Heuvel]

The man page is pretty clear I thought

"By default, changes to the currently running kernel configuration are applied immediately. Some changes cannot be applied without a reboot; if any such changes are requested, or the -h flag is given, all changes on the kctune command line will be held until next boot."

and under -c "... kctune will view or change tunables in the currently running kernel configuration."

But why speculate just ask for the full report. Use for example: kctune -v dbc_min_pct

fwiw,
Hein

[Adam Garsha]

"Running configuration" is a little ambiguous. Does it mean just in memory or also persistent? I assume persistent now based on your response, correct?

[Adam Garsha]

OK, I went and just tried it--which I don't like to ever do without strong confidence in outcome. And the answer is: it asks you what you want to do during execution. Namely, save it or not.

I'll give points for above and close this out. Sorry for asking a naive question, frankly, it was't clear to me.

[Adam Garsha]

See above.