A network interface driver must always be loaded with the parameter InterruptThrottleRate=1, and the setting has to survive a reboot. Where do you record it?
LPIC-1 Exam 101-500, objective 101. System architecture medium
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How these questions are written — where each question comes from, what the verification ledger records, and what happens when one is found wrong.
The options
Correct An `options e1000e InterruptThrottleRate=1` line in a .conf file under /etc/modprobe.d/
Correct. modprobe reads every *.conf file in /etc/modprobe.d/, and an `options` line supplies parameters whenever that module is loaded, whether by hand or automatically by udev.
Not correct A line naming the module in a .conf file under /etc/modules-load.d/
Wrong. Files in /etc/modules-load.d/ list module names that systemd-modules-load should load at boot. They take module names only, so there is nowhere to put a parameter.
Not correct An `insmod` invocation with the parameter appended, added to /etc/rc.local
Wrong on two counts. insmod loads a single object file and resolves no dependencies, and rc.local is a legacy compatibility hook that runs late, long after udev has already loaded the driver.
Not correct A `dev.e1000e.interrupt_throttle = 1` entry in a file under /etc/sysctl.d/
Wrong. sysctl.d files set kernel tunables exposed under /proc/sys/. Module load-time parameters are not part of that tree.
Why
Module parameters are supplied at load time, so they must be configured where the loader looks: modprobe reads /etc/modprobe.d/*.conf (plus the distribution's files under /usr/lib/modprobe.d/ or /lib/modprobe.d/) and applies any `options MODULE param=value` line for the module being inserted. The same directory holds `install`, `blacklist` and `alias` directives. If the module is also loaded from the initramfs, the image has to be regenerated for the new option to apply that early. `modinfo -p` lists the parameters a module accepts, and /sys/module/<name>/parameters/ shows the values currently in force.
Where this comes from
- Cited
- manual page modprobe.d(5)
Practise this
Reading one question is not practice. The trainer will draw a short set from objective 101 and space the ones you get wrong.
More questions on this objective
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