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Questions tagged [linux-kernel]

The Linux kernel is the operating system kernel used by the Linux family of Unix-like operating systems. It is one of the most prominent examples of free and open source software.

The Linux kernel is the operating system kernel used by the Linux family of Unix-like operating systems. It is one of the most prominent examples of free and open source software.

The Linux kernel is released under the GNU General Public License version 2 (GPLv2) (plus some firmware images with various non-free licenses[citation needed]), and is developed by contributors worldwide. Day-to-day development discussions take place on the Linux kernel mailing list.

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Optimize linux for serving http static content

What would be the system tunables to enhance serving static content? Like increase/decrease swappines, how to max out disk caching and so on...
Calin Don
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Tracking huge buffer usage under Linux

I'v a Linux server running under Debian Lenny with 4Go of RAM. It doesn't run a large number of stuffs: Postfix/spamassassin (daemon mode) Bind9 KVM (one guest - 1Go of RAM for it) Every day at exactly 3:05 UTC, the server completely drop to ground…
Henry-Nicolas Tourneur
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What can be the reason for "Invalid module format"?

I'm following the steps to compile kernel 2.6.32 from source, and have no problem to go the the last step: ... make modules_install make install And I've also configured grub.conf correctly. But when I try to reboot,it fails to boot: insmod: error…
yum
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best practice after upgrading the kernel

Greetings ... I need to know what anyone should do after upgrading the kernel ? How to do quick check if the kernel is suited for the server's softwares , check whether if kernel is compilable with cpanel that currently installed etc .
Libyano
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Symlink doesn't work when pointing to file on different mount point using relative path

On one of my machine, cd /var/lock fails despite that /var/lock is a symlink to an existing directory ../run/lock. After further investigation, I found that any symlink pointing to another mount point using relative path will fail. This only happens…
yyyy
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Page cache in Kafka

We are receiving alerts for kafka memory utilization in our kubernetes cluster and analysing it seems that most of the memory is page cache. I am aware that kafka uses loads of page cache for IO performance and reads/writes are cached before…
Putharekulu
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Debian: Kernel update using APT - reboot required to take effect?

Suppose I update the kernel of a running Debian system using apt-get upgrade linux-image-amd64 to a higher minor version number (e.g., 5.10.10 to 5.10.11). Do I have to reboot the Debian server in order for the update to take effect?
manifestor
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Couldn't load target `NOTRACK':No such file or directory

I am trying to add a IP table rule. iptables -t raw -A PREROUTING -j NOTRACK But when I am executing this I am getting below error: iptables v1.8.4 (legacy): Couldn't load target `NOTRACK':No such file or directory
Bhupendra Nath
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perf gives high copy_user_generic_string and clear_page_rep

I am building a server in c++ that reads a lot from disc. When recording with perf I get this report: 28.20% server [kernel.kallsyms] [k] copy_user_generic_string 18.14% server [kernel.kallsyms] [k] clear_page_rep …
joscul
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Kernel TCP tuning for buffer overrun and packet collapse

We have a Nginx+Ruby application where the data between Nginx and the application are interfaced through a socket. As part of performance improvement, when we analyzed the netstat statistics on the application side we saw these: 5334 packets…
madu
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Changing your kernel in AWS appears to break boot sequence (grub config issue?)

Using Ubuntu 20.04 on AWS (ec2), I wanted to change my kernel from AWS to a generic one. When I try it the suggested way with changing the Grub Config, it stops the machine. This is because Jibri (Jitsi Video Recorder) requires the use of ALSA and…
PaltryDrought
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Why does my Linux Kernel have missing directories / files that are crucial for ip_tables to run?

as mentioned in the header - my Linux Kernel seems to be missing files / directories that are crucial for iptables to run properly. I'm able to temporarily resolve this by reinstalling my kernel, but it's not a permanent resolve as after a reboot…
Landon Miller
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What is the purpose of /sys/block/sd?/device/rescan?

I need to "rescan" the SATA bus of our Linux server in search of a hotplug device that doesn't show up. I've seen an old question on the topic (How do I make Linux recognize a new SATA /dev/sda drive I hot swapped in without rebooting?) and the…
Sylvain Leroux
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Maxing Linux networking performance on multiqueue NIC

According to https://lwn.net/Articles/629155/ the Linux kernel, "can only forward something between 1M and 2M packets per core every second" - but how good Linux is at scaling across dozens of cores then? Say I have a multiqueue(128 rx+tx pairs)…
Dmitry Sychov
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How does the linux kernel identify storage devices or any devices in general?

1 Problem: Today I encountered a strange behavior when trying to benchmark SSD's with a Raspberry PI and having two SSD's with the same label. 2 Setup: My setup is like this: My Raspi runs Ubuntu 2004 - the root file system is on a Samsung T5. On…
Andrino
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