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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CentOS: After Kernel Update system does not boot (/dev/md2 does not exist)

after doing a kernel-update (only via yum update) my centOS 7 (64bit) does no longer boot. I now booted into rescue-mode and tried to mount /dev/md2 - this worked fine: Any ideas what I could do here?
MyFault
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Segfault in libc-2.19.so with Webmin

I recently upgraded the kernel one of my Debian 8 servers which has Webmin+Virtualmin installed on it. The server had usual Virtualmin backups setup which used to work fine before the upgrade, but post the upgrade the backups stopped working with no…
GeekTantra
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Linux vm.vfs_cache_pressure affect page cache or not?

I want to limit page cache in linux. Some documents say increase vm.vfs_cache_pressure to control the kernel reclaim memory. I try, but not work. Linux/Documentation/sysctl/vm.txt say "Decreasing vfs_cache_pressure causes the kernel to prefer to…
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Why takes CLEARING swap soo long?

Why is moving from RAM to swap fast and from swap to RAM very slow? When I run program that needs more memory that is available, I see that the RAM is prety quickly "cleaned" by moving unsused (=the least accessed) pages to swap. But then when I…
mvorisek
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How to reliably capture Linux kernel log messages in case of a system debilitating crash (BUG, panic)?

I'd like to have access to the lines/tracebacks/whatever whispered by the kernel right before dying. This has proven problematic, because all interfaces I have access to become disabled. Post-reboot, systemd journal has not been able to record…
lkraav
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Can't get rid of mystery kernel

Just noticed that despite having the kernel updated regularly, the version in use is quite outdated: $ uname -a Linux test 2.6.31-302-rs #7 SMP Thu Oct 29 22:57:03 UTC 2009 x86_64 x86_64 x86_64 GNU/Linux Strangely, this version of the kernel…
ejain
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When does an upgrade update the Ubuntu kernel?

I'm a little confused by Ubuntu/Linux kernel updates. Coming from a Windows background I sort of expect all updates to be available via the update manager, in the case of Ubuntu apt/aptitude. Yet if I look at the kernel versions of all our servers…
user1167223
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strace not showing anything for thread at 100% 'system' CPU

I'm having difficulty with my Python app going to 100% 'system' CPU time across multiple threads for up to 10+ seconds. My (limited) understanding is that 'system' CPU time is time spent in the kernel. strace shows what kernel calls are being made…
Damon Maria
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rcu_sched self-detected stall on CPU on Debian server

My server is online since October 2014. Debian GNU/Linux 7.6 uname -r 3.10.23-xxxx-std-ipv6-64 It was working fine till last night. Last night it bacame unresponsible. I rebooted it from dadata center control panel end everythin was OK. This night…
user1406271
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PCIe card memory regions ignored on linux kernel 3.13

On my system, with kernel 3.13.0-32-generic (Ubuntu Server 14.04.1 LTS) installed, one of the PCIe boards in the system (06:00.0) is having it's memory regions ignored: Interrupt: pin A routed to IRQ 10 Region 0: Memory at (32-bit,…
Dave
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Running multiple ubuntu (or other distro) inside Docker containers on CoreOS, is this efficient?

From what I have read I believe CoreOS to be a bare-bones Linux distribution which essentially facilitates running Docker containers that contain any applications or services that you require. From the CoreOS documentation I gather that the…
rgvcorley
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Warning :mounting fs with errors, running e2fsck is recommended

Linux server will hang and when I restart it will take around 2 hours to come up and resume normal operations. I checked the system log files and found mounting fs with errors, running e2fsck is recommended I found some solution here, which says…
Manju Kb
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task fstrim blocked for more than 120 seconds

I'm experiencing random crashes on my system. I've narrowed the problem to the fstrim program that's launched weekly by cron. In the console, I've got a set of blocked tasks among whigetch I find fstrim. (other blocked tasks are jdb2/dm, rs:main…
Olivier
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dummy network interface in Linux

When i create a dummy network interface and then bring it up it show up being in UNKNOWN state: root@5b8dd2855a9c:# ip l a boom type dummy root@5b8dd2855a9c:# ip l show boom 58: boom: mtu 1500 qdisc noop state DOWN mode DEFAULT …
milosgajdos
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"Nosy Neighbor" and the CFQ scheduler

I'm trying to understand how does using CFQ affects the "Nosy Neighbor" problem. I'll ask it a bit naively, can a "Nosy Neighbor" even exist when using CFQ? Isn't that CFQ should make sure all processes(VMs) get fair slices of storage time? If so,…