Server Fault Stack Exchange
Server Fault Stack Exchange

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.

585 questions
9
votes
1 answer

Why does Linux answer to ARP on incorrect interfaces?

I have the following Linux networking setup: there is an eth10 network interface with the assigned address 10.11.0.1/24. Then there is a tap0 network interface with assigned dummy address 0.0.0.1/32 (I assigned a dummy address to bring the interface…
juhist
  • 302
  • 1
  • 3
  • 10
9
votes
2 answers

How does one diagnose Linux LACP issues at the kernel level?

Is there an underlying administrative or diagnostic interface to the Linux bonding driver to determine what is going on internally? I've used link aggregation between Linux boxes and Cisco switches for many years. Periodically I run into a dead-end…
jjoganic
  • 91
  • 1
  • 1
  • 3
9
votes
1 answer

Why can't QEMU allocate the memory if the Linux caches are too big?

If I use my machine [Ubuntu 16.04 64 bit, kernel 4.4] for a while, QEMU needs the kernel caches to be dropped, otherwise, it won't manage to allocate the RAM. Why does it happen? This is a sample run: ~$ free -m total used …
Marcus
  • 242
  • 1
  • 3
  • 10
9
votes
2 answers

How do I set the default kernel parameters in CentOS for all existing and future kernels?

I'd like to remove the rhgb and quiet kernel parameters which are used by default when the kernel is booted in CentOS 6, but I want this to apply to all currently installed kernels as well as any kernels installed in the future. I need to do this…
mgorven
  • 30,615
  • 7
  • 79
  • 122
9
votes
2 answers

Linux Kernel Versioning: Debian Sid vs Ubuntu Precise

I have setup two machines: On one machine I have installed Ubuntu Precise 12.04 beta and dist-upgraded to the latest packages. On the other machine I have installed Debian Sid Unstable and dist-upgraded to the latest packages. On the Ubuntu machine…
Andrew Tomazos
  • 193
  • 5
9
votes
1 answer

Flush processes consume too much of CPU

The Server is EC2 Instance, it stands for saving files to NAS (NFS) from HTTPD. The processes like flush-0:32 consume over %90 of CPU and load average: 65.50, 64.02, 66.59. According the graph, it's increasing every day while initial load average…
Roman Newaza
  • 632
  • 4
  • 13
  • 23
8
votes
0 answers

Multithreading with multi-queue NIC on SMP system

How are packets scheduled from network interface queues to CPUs, then onwards to threads for processing? What needs to be considered when it comes to how packets are hashed across queues, hardware interrupts vs softirqs, CPU/memory/app/thread…
svenx
  • 416
  • 3
  • 4
7
votes
1 answer

How to disable ipv6 support in Linux entirely?

We are currently setting up a some local network servers to run in a full ipv4 network. I can be sure, that this network don't have ipv6 support, and never will. Next to that, partially because of a command from higher organisational…
user266008
7
votes
3 answers

Linux: echo 3 > /proc/sys/vm/drop_caches takes hours to complete

I have a Thecus N8900 NAS, which is a Linux based file server, providing files via NFS to six clients. For some reason that Thecus support has yet to explain, it runs a script that checks /proc/meminfo every 60 seconds and if the disk cache exceeds…
rmm
  • 81
  • 1
  • 2
7
votes
4 answers

linux initcwnd and initrwnd via /etc/sysctl.conf

Folks, As we know, the 3.x kernels have higher TCP default connection values, such as initcwnd and initrwnd. For 2.x friends, is there a way to set these in /etc/sysctl.conf instead of the ip route way? Instead of the following: sudo ip route…
CMag
  • 707
  • 2
  • 11
  • 32
7
votes
5 answers

MySQL 5.5 degraded performance in linux kernel 3.2 compared to 2.6

Our database servers (mainly based on the Debian stable packages (=currently Wheezy) seem to have about 4 times more load for the same workload in kernel 3.2.0-4-amd64 then in it's previous 2.6.32-5-amd64 kernel. With all packages the same & booting…
Wrikken
  • 981
  • 9
  • 22
7
votes
5 answers

Convey multicast (to another LAN) through WAN disabling multicast

My Server and Client softwares run both on Linux. The Server broadcasts multicast, the Client listens multicast. My Client has to migrate to another site, and unfortunately multicast is not allowed between the two sites :-( How to convey multicast…
oHo
  • 545
  • 1
  • 6
  • 14
6
votes
1 answer

mdadm - stuck reshape operation

I have a 3 disk RAID 5 array that I tried to add a 4th disk to. mdadm --add /dev/md6 /dev/sdb1 mdadm --grow --raid-devices=4 /dev/md6 This operation started successfully and proceeded until it hit 51.1% cat /proc/mdstat Personalities : [linear]…
Cephas
  • 443
  • 1
  • 4
  • 10
6
votes
2 answers

Linux (non-transparent) per-process hugepage accounting

I've recently converted some java apps to run with linux manually-configured hugepages, as described here. I point out "manually-configured" because they are not transparent hugepages, which gave us some performance issues. So now, I've got…
Dan Pritts
  • 3,221
  • 26
  • 28
6
votes
3 answers

Kernel updates without rebooting

Similar to some of the topics touched on in this question, Is it important to reboot Linux after a kernel update?, I was curious if there was a way in which one could apply kernel updates to the system without rebooting. I know that there is a…
John
  • 2,276
  • 7
  • 44
  • 60
1 2
3
…
38 39