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
2
votes
1 answer

Ubuntu VM will not boot up with Kernel newer than version with Microsoft Hyper-V Hypervisor on Windows Server 2012r2

I have two Ubuntu Server 18.04 LTS VM's running on Hyper-V on Windows Server 2012r2. Additionally, I have two Windows VM's (1 10, 1 7) on the same Hyper-V server. The Windows VM's have not experienced this problem. They both exhibit the following…
tkr65536
  • 51
  • 4
2
votes
1 answer

rcu_sched self-detected stall on CPU + watchdog: BUG: soft lockup - CPU#3 stuck for 22s

Being unable to ssh into a machine I connected it to a monitor and found the following: The machine is running Ubuntu Server 18.04 LTS and is a first generation 8 core Ryzen 1700. I've restarted the machine since and it works fine but am not sure…
Greg
  • 1,657
  • 5
  • 27
  • 38
2
votes
1 answer

what is the best practice when rescanning scsi disks reliably in linux?

I'm constantly having to make SAN changes which means that I am also constantly having to rescan the scsi bus so that my various changes are reflected in the machines I've exported disks to. I've been plauged for some time by various facets of…
Rusty Weber
  • 472
  • 8
  • 21
2
votes
1 answer

How can iperf reporting packet loss in udp

Iperf is the well known tool to calculate throughput. When i tried udp throughput using iperf on my linuxpc, It reported that 10% of packet loss. In UDP protocol, data gram did not receice any acknowledgements. But, in what way iperf is reporting or…
Vijay Kalyanam
  • 121
  • 1
  • 2
2
votes
1 answer

zram filesystem reports different usage at device level to that reported by the filesystem

We have an 80GB zram device defined on our host, and within this a 170GB ext4 filesystem: echo 170G > /sys/block/zram0/disksize echo 80G > /sys/block/zram0/mem_limit /usr/sbin/mkfs.ext4 -q -m 0 /dev/zram0 /usr/bin/mount /dev/zram0…
Steve Shipway
  • 740
  • 5
  • 17
2
votes
1 answer

How to restrict root to access a directory used by other user with selinux

I want to restrict the root to access a folder/directory which is created by another user.So that only that user can access that folder not even root. Is there any selinux configuration to do so this as I am not so known to selinux.
Ravi
  • 21
  • 1
  • 3
2
votes
2 answers

Opening a linux-crashdump dump with crash?

So I've been trying to debug a weird intermittent kernel crash for a server running Ubuntu-Server 16.04, which has had me stumped for ages, and so I installed and setup linux-crashdump following the Ubuntu wiki crash dump recipe. After waiting for…
Haravikk
  • 267
  • 4
  • 12
2
votes
1 answer

How irqbalance works

Does irqbalance add kernel module? How a user space daemon is able to assign interrupts to different processors? If it is a user space process that is doing it, won't kernel to user space context switch delay the interrupt processing?
kalyan
  • 249
  • 1
  • 3
  • 11
2
votes
2 answers

Error adding iptables snat or dnat rules in linux

I am using Arch Linux (the 32 bit version) on a Raspberry Pi 3. When I attempt to add any -j SNAT or -j DNAT rules to iptables, it doesn't work - I receive an error iptables: No change/target/match by that name I don't normally have a problem with…
bao7uo
  • 1,704
  • 12
  • 24
2
votes
4 answers

Yum wants to remove and re-install my kernel. Is this safe?

I am running CentOS 7 and I just ran yum update. Something in the resulting output makes me hesitate to type y to proceed with the update. Here's what it…
Lightness Races in Orbit
  • 388
  • 2
  • 5
  • 18
2
votes
2 answers

Inode usage gone up to 100% hence can't uninstall any package

My server's inode usage has gone up to 100% due to which I am not able to uninstall extra linux-kernel-headers and linux-kernel-images $ df -i Filesystem Inodes IUsed IFree IUse% Mounted on /dev/xvda1 524288 523970 318 100% / none …
Shailesh Sutar
  • 1,517
  • 5
  • 23
  • 41
2
votes
2 answers

Troubles with booting xen VM in Hyper-V

I have raw image with xen hypervisor powered Virtual Machine (ubuntu 12) I converted it to vhdx (Hyper-V) format and now trying to boot it: Grub says error 13 invalid or unsupported executable format Probably, due to para-virtualized VM style this…
timhok
  • 21
  • 4
2
votes
1 answer

Does IPv6 equal cost multi-path routing work on Linux Kernels?

End goal is to get per-packet ipv6 udp load balancing by having multiple servers with the same /128 set on the lo interface. To start, just trying to get it to work with static routes, then will start to explore BGP with Quagga or some similar…
NeedISayMore4
  • 21
  • 1
2
votes
1 answer

Why limit the total amount of shared memory available?

I have some large memory processes that share memory on a CentOS 7 system. I am tuning the memory system for them. For kernel.shmmax and kernel.shmall the RedHat documentation states: kernel.shmmax defines the maximum size in bytes of a single…
Jeff Kubina
  • 427
  • 1
  • 4
  • 14
2
votes
2 answers

Martian sources from my public IP

These days I get some Martian packets in the kern.log: Jul 7 02:28:20 box14932 kernel: [789192.798073] IPv4: martian source XXX.XXX.XXX.XXX from 10.91.12.01, on dev eth1 Jul 7 02:28:20 box14932 kernel: [789192.798095] ll header: 00000000: 44 a8 12…
user2074224
  • 23
  • 1
  • 4
1 2 3
…
38 39