Questions tagged [linux-kernel]
This tag is for questions about the internals of the Linux kernel itself - particularly about use or configuration of kernel modules or drivers.
487
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Installing VirtualBox in linux via a script with also includes signing kernal modules
I have a linux VM (ubuntu 20.04) with secure boot settings active. Basically I need to install virtualBox and then create multiple VMs via virtual box via script only. No manual intervention should be ...
0
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0
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43
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Pgbouncer: Multiple Instances on same host receiving same TCP connection when using SO_REUSEPORT
I was able to setup two pgbouncer instances for database connection pooling, on a single VM (CentOS 7.0) listening to same port (6432) on two different TCP socket (I believe) using Linux Kernel ...
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1
answer
431
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Kernel panic error in Parrot Security, how do I fix it I tried everything
I can't boot into the new 6.5 kernel.
I am using Parrot Security on my laptop and it recently upgraded from kernel 6.1 to 6.5 but I can't boot into the 6.5 kernel.
When I try update this happens:
...
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1
answer
92
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Tell Linux scheduler not to use certain CPU cores at runtime?
I want to absolutely remove certain CPU cores from Linux scheduler.
All I found on the Internet is adding isolcpus to grub with rebooting.
But it there a way to do it at runtime (without reboot)?
34
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3
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4k
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Why does the Linux SCSI subsystem drive hardware not obviously related to SCSI?
Without knowledge, I would normally expect SATA, SCSI and USB Mass Storage to be driven by different drivers. In Linux however, the SCSI subsystem drives all of them.
Why does Linux use the SCSI ...
0
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1
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214
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Install specific Linux kernel headers
I'm learning how to write a module, and when I initialize "make", I get
make[1]: *** /lib/modules/6.6.6-060606-generic/build: No such file or directory. Stop.
With this Makefile:
obj-m = ...
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0
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16
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How can I delete just one queue in htb?
I would like to delete just one queue in htb when having two. My script would be the following one:
TC=/sbin/tc
IF=wlan0 # Interface
DNLD=1mbit # DOWNLOAD Limit
UPLD=1mbit ...
1
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1
answer
344
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SSD read/write error on ASUS Vivobook S15 S533 (11th Gen Intel) running Ubuntu 22.04 after update
I have Ubuntu 22.04 upgraded from 20.04 installed in 2020. This machine]1 worked well with kernel 5.15.0-43. After recent update (2023.11.28) it often crashes random with I/O error. While crashing it ...
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1
answer
3k
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How do I install the newest Linux kernel (6.5 currently) on Linux Mint (21.2 Victoria currently)
I know how to use Mainline, and can install that kernel, but the headers require a newer libc (>= 2.38) than what’s installed (2.35-0ubuntu3.1), and I need the headers to build two modules (...
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472
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Configure amount of reserved memory for Linux kernel
I am running Linux on an embedded device with 64MB of physical RAM. Linux prints the following message when it boots:
[ 0.000000] Memory: 58944K/65536K available (3072K
kernel code, 576K rwdata, 832K ...
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0
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93
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Using ebtables with hostapd to block outbound access from an IoT network
I have a Raspberry Pi set up to control a number of local IoT devices, and needed them connected to the Internet to set them up initially, but want to prevent them from "phoning home" to a ...
0
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0
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60
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executing bash script on rotation with iio-sensor-proxy
I have a Tablet-laptop where i want to disable a gnome extension when the screen is rotated.
Auto-rotation works via iio-sensor-proxy.
it would be stupid to poll monitor-sensor constantly for resource ...
0
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1
answer
617
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How to install specific kernel version on ubuntu, which disappeared already from repo `deb http://archive.ubuntu.com/ubuntu/`
My current kernel version is "5.15.0-73-generic". There is some "leading" crypto company, which offers product to strenghten company machines, and our company bought their product ...
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1
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146
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Linux from Scratch: can't connect to home WLAN
I started building LFS to learn more about linux internals. I struggel to configure WLAN and can't even narrow down the problem.
On my laptop I have a dual boot (ubuntu 22 and LFS 11.3) and on ubuntu ...
0
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1
answer
36
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Why does it go through netfilter postrouting when visiting local ports?
Environment:
[root@VM-32-4-centos ~]# uname -r
3.10.0-514.26.2.el7.x86_64
I have set log printing in the following chain:
[root@VM-32-4-centos ~]# iptables -A INPUT -p tcp --dport 8000 -j LOG --log-...
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1
answer
499
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Can't login to Ubuntu in virtual machine
When I updated the system, and then I restarted the machine, I don't know why it's showing this picture:
Can someone solve this problem?
I tried to restart the machine again and again, but its still ...
1
vote
1
answer
486
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Linux Kernel Compilation: Debug info generated albeit disabling `DEBUG_INFO`
I regularly compile Linux kernel on my own. For speed issues, I would like to omit debug information.
A minimal way that reproduces the problem is
make localmodconfig
scripts/config --disable ...
0
votes
0
answers
391
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Not turning off completely the system. its going to the halt mode in Fedora
some time when i want to shutdown the system in fedora, the system not shutdown completely.
in this problem screen is off but fan is working
Not sure if this is relevant,but there are several errors ...
1
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2
answers
518
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LFS 11.2 on Ubuntu Server 22.04: chroot: failed to run command ‘/usr/bin/env’: No such file or directory
I have been following the LFS 11.2 guide and it has gone smoothly up until the chroot part. Although the symlinks have created properly i.e. relative to the LFS directory, the error is still ...
3
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2
answers
4k
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Fedora 37 VirtualBox Error "vboxdrv kernel module is not loaded" and "Kernel driver not installed (rc=-1908)"
(I already tried things from answers in similar questions to this one)
Fedora Linux 37 (Workstation Edition) x86_64, kernel: 6.0.7-301.fc37.x86_64
I installed VirtualBox with sudo dnf install ...
0
votes
1
answer
643
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Disable autoremove of old kernel versions on Fedora 37
Somewhy i can't boot on kernel version higher than 6.0.7-301 (more here).
Recently Fedora automatically downloaded kernel 6.1.10, and after a few days 6.1.11. Both of them, as i said, i can't use for ...
0
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1
answer
821
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Cannot upgrade linux kernel due to space, but cannot remove older ones
uname -r
5.15.0-60-generic
My apt upgrade is failing with:
Reading package lists... Done
Building dependency tree
Reading state information... Done
Calculating upgrade... Done
Get more ...
1
vote
0
answers
224
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Second nvme missing in /dev/ after kernel upgrade
I have been pushing back my kernel upgrades on my arch machine because after upgrading from 5.14.9 my secondary nvme is not populated into /dev/ anymore.
But I want to tackles this now, hopefully with ...
0
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1
answer
783
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Fedora 37 Infinite boot on kernel 6.1.9-200 (and higher)
Fedora Linux 37 (Workstation Edition) x86_64
GNOME 43.2
Kernel: 6.1.7-200.fc37.x86_64
After selecting kernel 6.1.9 while boot (which is chosen by default) I'm having infinite black screen with ...
0
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0
answers
172
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Can we ditch the Linux initial ramdisk if we don't use loadable modules?
I'd like to boot an embedded machine without using a ramdisk image. I understand one of the reasons for the ramdisk is so it can load the filesystem module needed for accessing the root partition (to ...
1
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0
answers
283
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net.core.netdev_max_backlog - what's the impact when set too HIGH?
I'm working on optimizing and right-sizing my EC2 syslog-ng servers and have some carryover settings in our ansible playbook for kernel settings that were used on "in-house" data center ...
0
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0
answers
173
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How can I install Kernel 5.17 on CentOS 7?
On a CentOS 7.9 installation I have some troubles running newer CPUs, e.g Ryzen 5 5600G (with included graphics).
I concluded that it is the Kernel because it boots with certain versions, with kernel ...
2
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1
answer
410
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Is there anything preventing modifying linux's tcp stack to have over 65,535 ports?
I was reading this and started to wonder of there was anything preventing me from just modifying a copy of the linux tcp stack to support more than a 16-bit header to allow for more ports. Would this ...
3
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1
answer
6k
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High System CPU usage on Linux
We have an unusual problem where some of our Linux servers are going into a state where the CPU utilisation is very high and when we dig down, most of it is in kernel space. The %sys utilisation is 80%...
0
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1
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3k
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Change default kernel for an AWS instance running Ubuntu 18.04
1. Problem summary
I have an instance on AWS running Ubuntu 18.04. The kernel version is 5.4.0. I have installed kernel 4.15.0 but I am failing to set it as the default.
2. What I have tried
A) I set ...
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1
answer
135
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Can't open pseudoterminals from local following an update on Arch
I did a complete update (via yay->pacman), restarted, and now I seemingly can't open any pseudoterminals. All I can do is switch to TTY/teletype terminals. If I try to open a terminal app, it just ...
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0
answers
683
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Fedora 35: Switch back to stock kernel?
A few months ago I built a new machine and installed Fedora on it. At the time, 5.15 was the latest "stock" kernel, but I needed some of the Alder Lake fixes/improvements from 5.16 and 5.17,...
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1
answer
149
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linux-ck-ivybridge stuck on 5.12.18-1
I use the CPU optimized kernel linux-ck-ivybridge on Arch Linux using the repository below, however for unknown reasons pacman has stopped upgrading the kernel since July 2021.
It is also not listed ...
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0
answers
2k
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Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000005
I'm pretty new to embedded linux and I would really appreciate a bit of help. I'm trying to run a linux kernel on the risc-v fpga.
I built linux 5.0.0 with busybox initramfs and compiled with this ...
1
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1
answer
3k
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UEFI Variable Storage (removing /sys/firmware/efi dump files) when Kernel Variables CONFIG_EFIVAR_FS & CONFIG_EFI_VARS both =y as in Ubuntu 20.04
In the Arch Wiki I see that the two kernel variables CONFIG_EFIVAR_FS & CONFIG_EFI_VARS should be set =y and =n respectively. Arch says, "This option should be disabled to prevent any ...
0
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1
answer
86
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KVM 3.1.1 installation
I have a requirement to install KVM 3.1.1 on RHEL7 or 8.
When I am checking I found that qemu-kvm is automatically installed on RHEL8 and the version is 4.2.
It would be great if anyone can share the ...
0
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0
answers
121
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Linux System goes back to vendor's default config after reboot
I hope everyone is 0k.
I have embraced Linux systems for around 3-4 years now, I am not what you called an expert nor a rookie.
Anyway, I have a NAS device running BusyBox v1.20.2 - Linux version 3.2....
1
vote
1
answer
3k
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How to use dracut in chroot environment established through SLES15 Rescue boot image?
To fix an unbootable SLES15 system, I booted the Rescue image, mounted the existing system to /mnt, and then did chroot /mnt (I'm leaving out the details, as those are probably known (or found in How ...
2
votes
1
answer
918
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HDD I/O error after high multithreading usage
I have a computer with 64 physical cores (AMD Ryzen Threadripper PRO 3995WX 64-Cores), with two threads per core capability (that is, 128 logical cores), running on Ubuntu 20.04.3 LTS. Recently, I ...
3
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0
answers
2k
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Connecting two monitors at boot causes Linux kernel to hang when enabling KMS
When two monitors are connected at boot, the Linux kernel completely hangs at fb0: switching to i915 from EFI VGA. The screens stay on and continue displaying the last message, but everything is ...
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1
answer
2k
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Defragment BTRFS to change the compression level
I can do:
btrfs filesystem defragment -rvf -czstd ./
But not:
btrfs filesystem defragment -rvf -czstd:1 ./
I get the error:
ERROR: unknown compression type zstd:1
Is there any way to change the ...
1
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1
answer
4k
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How to disable features in an xfs file system to make it compatible with an older kernel?
I am using a rocky8 system on which I need to build, install and run a 3.10 kernel.
I managed to get it to build and install, but when booting it up I get the error message:
XFS (sda1): Superblock has ...
2
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1
answer
442
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linux-firmware apt package VS fwupd tool: Are they doing same thing?
I noticed here two things about firmware:
1. apt list linux-firmware
https://launchpad.net/ubuntu/+source/linux-firmware
$ apt list linux-firmware -a
Listing... Done
linux-firmware/focal-updates,focal-...
0
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1
answer
632
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centos7 crash when systemctl start docker successed
[phenomenon]
1、I enter the command systemctl start docker from centos7, the centos7 crashed after docker successfully started.(It's reproducible)
2、Docker used to be available until I ran 3 ZooKeeper. ...
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0
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247
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Linux USB mass storage gadget issues with large drives
I'm trying to make a linux device act as a large USB drive with a USB port in OTG/device mode. The g_mass_storage module works well with backing files up to 2Tb of size, but I can't find a way to ...
0
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1
answer
431
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Remove kernels installed from source from Fedora 34
I have compiled and installed a linux kernel from source, installing it with sudo make install, but the system failed to boot.
How can I remove the kernel installed as such?
0
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0
answers
1k
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iptables use to ignore TCP packets. Not reject But ignoring including syc comning in but nothing is done
I like to simulate TCP connection in Server-client using layer 2 sockets for receiving packets and sending packets using Packet MMAP or DPDK or netfilters and dev_xmit for this to come any close to ...
0
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1
answer
451
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Is it possible to build Linux kernel inside an LXC container?
I would like to build an optimized kernel for a machine that runs Ubuntu 20.04 but in my scenario I cannot "pollute" the Linux installation with all the dependencies required to do the build....
0
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0
answers
825
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location of kernel source code directory in centos 7
I wanted to enable a specific feature in centos 7 kernel. What is the exact location of kernel directory in centos 7.4, so that I can lauch this command successfully inside the kernel source code ...
0
votes
1
answer
372
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Linux Kernel support for ARM Cortex-A78
I am planning to boot Linux for an ARM Cortex A78 based system.
And I have some doubts about the same.
1. Which kernel version should I select ?
I checked 5.4.112, 5.10.30, 5.11.14, 5.12-rc7 kernels, ...