1
vote
2answers
35 views

How to check if Ubuntu 14.04 Kernel has TPROXY

I'm using Digital Ocean's Ubuntu 14.04 image and needs the kernel to be compiled for TPROXY. Is there a way to check whether the current kernel supports TPROXY?
0
votes
1answer
178 views

GRUB “Some modules may be missing from core image” Error

one HDD crashed from my RAID and I added a new HDD. Now I wanted to install GRUB to the new HDD: with "grub-install /dev/sdb" I get these errors: Installing for i386-pc platform. grub-install: ...
0
votes
0answers
21 views

How do I configure kdump with extra_modules on ubuntu?

I need to configure extra modules to load with kdump (specifically, vga16fb.ko). On RHEL systems it's in /etc/kdump.conf, but ubuntu doesn't have this file. I've looked in /etc/default/kdump-config, ...
1
vote
1answer
168 views

preventing ipmi kernel drivers from loading

I'm trying to prevent the ipmi kernel modules from loading on a server with a SuperMicro X8DTG-D motherboard running Ubuntu 14.04. My motivation for doing so is that the modules sometimes seem to take ...
0
votes
1answer
40 views

Ubuntu 13.10 server has no kernels

Something has gone wrong and now we no longer have a Linux kernel (not even recovery mode) installed. GRUB is still there, but it runs the memory test. How can I fix this? Everything I've looked at ...
0
votes
1answer
30 views

In sysctl.conf settings, what is the difference between 'all' & 'default'?

In context of sysctl.conf settings, what is the difference between (all vs. default) like net.ipv4.conf.all.accept_source_route & net.ipv4.conf.default.accept_source_route in sysctl settings ? ...
0
votes
1answer
170 views

Modifications to sysctl.conf in openVZ container, do they even take effect?

I'm following a security guide(http://www.thefanclub.co.za/how-to/how-secure-ubuntu-1204-lts-server-part-1-basics) to strengthen my OpenVZ based VPS webserver running Ubuntu 12.04 , a part of that ...
2
votes
1answer
484 views

“kernel: Cannot read proc file system: 1 - Operation not permitted” — millions of such messages each minute in kern.log on OpenVZ VPS? [closed]

I'm seeing repeated never ending such messages in kern.log on my OpenVZ ubuntu 12.04 server. Mar 2 06:23:33 localhost kernel: Cannot read proc file system: 1 - Operation not permitted. Mar 2 ...
0
votes
2answers
920 views

What is using the RAM on this Ubuntu 12.04.2 server?

I have two servers in a pool with Nginx, PHP5-FPM and Memcached. For some reason, the first server in the pool seems to inexplicably lose about 2GB of RAM. I can't explain where it's going. A reboot ...
0
votes
1answer
365 views

Ubuntu 12.04 - Grub1 won't load new kernel

For some reason I can't get grub to load the new kernel. I tried removing the old kernels with aptitude and running update-grub but it still loads the old kernel - even though I've removed it! I ...
0
votes
4answers
145 views

If kernel type (64/32) is no indication of what bit your distribution is, how do I know what I'm running?

If kernel type (64/32) is no indication of what bit your distribution is, how do I know what I'm running? I'm on Ubuntu, and I just found out, to my surprise, you can use a 64 bit kernel on a 32 bit ...
1
vote
1answer
43 views

Enable CONFIG_VM_EVENT_COUNTERS without reboot/recompile

I have an Ubuntu 12.04 server that I am troubleshooting, and I would like to use iotop. However, it seems that 12.04 doesn't have CONFIG_VM_EVENT_COUNTERS enabled by default (required by iotop). I ...
1
vote
2answers
850 views

Can't build RocketRaid rr268x on Ubuntu 13.04

I am trying to build the kernel module for Ubuntu 13.04 but not having any luck, I have had this card working perfectly fine with 12.10 and the 3.5.0-27-generic kernel but since upgrading to 13.04 ...
1
vote
2answers
317 views

fix kernel on Xen Server hypervisor vps

I have a cloud server hosted at Rackspace, and they use Xen Server hypervisor. I was running Ubuntu 12.04, and really messed up by attempting to do a release upgrade manually. The hypervisor ...
1
vote
1answer
721 views

Kernel attempts to kill MySQL with sigkill

I'm running an Ubuntu server for MySQL. Server info Ubuntu 12.10 MySQL installed via apt RAM: 512M innodb_buffer_pool_size : 300M There is no other memory intensive application running on this ...
-1
votes
2answers
887 views

Why does Centos 6 have an older kernel than Ubuntu 12.04 [closed]

Hi can some one help me in understanding this. On Centos 6.2 its showing kernel as 2.6.32-220.el6.x86_64 whereas on Ubuntu 12.04 its showing as 3.2.0-23-generic. 3.0 kernel is one of the latest ...
1
vote
2answers
169 views

Different uname -a results

I am working on a multi-server system for a client. All of the servers are fresh installs (although two were installed a couple of months ago, five a couple of days ago). They are all supposed to be ...
0
votes
0answers
547 views

“sched: RT throttling activated” KVM host - what does this mean?

Ubuntu 12.04 64bit - under a KVM parent. 32 cores. So we seem to be having some load issues. We have noticed this line in kern.log: "kernel: sched: RT throttling activated" What does this mean? Is the ...
3
votes
1answer
818 views

AppArmor - root: “You do not have enough privilege to read the profile set.”

I'm trying to use AppArmor on a remote hosted Xen server with a custom built kernel. AppArmor appears to be running, but not correctly. For example if I run the following command as root: # ...
3
votes
1answer
2k views

Why OOM-killer invoked even when huge amount of RAM is free

On EC2 ebs-backed xlarge ubuntu instance, oom-killer is getting invoked. From /var/log/syslog output below, it appears that ZONE_NORMAL is running out of memory: Node 0 Normal free:11344kB ...
0
votes
2answers
780 views

systemtap not initializing correctly on Ubuntu 12 (Precise)

I work at a firm with a certain amount of legacy batch-processes. Some of that stuff is really leaky when it comes to database connections. I need to log every process in the system, which opens a ...
-1
votes
1answer
295 views

ubuntu 12.04 server comes with Odd Kernel Development version.How can it be upgraded??

I have downloaded latest ubuntu server edition but after installing its showing kernel of 3.2.0-23 Generic kernel,which is a development version. So how can i change to stable release with out ...
0
votes
2answers
358 views

What is the difference between -generic and -virtual kernels?

I am using XEN server 6.0 on machine and I want to install ubuntu 12.04 64bit. I want to optimize OS for running as VM. I choose to install from "http://archive.ubuntu.net/ubuntu/" but its showing ...
2
votes
1answer
218 views

Two server freezes with in two weeks

Two consecutive server freezes with in two weeks. We are running ubuntu 11.04 64bit on Intel(R) Xeon(R) E5620 @ 2.40GHz with 48 Gb RAM on 2.6.38-13-generic kernel dedicated server. after making ...
1
vote
0answers
287 views

Ubuntu - random reboot since 3.0 kernel

I have an Ubuntu Server that is now upgraded to 12.04 LTS server. Ever since I've upgraded from 10.10 to 11.04, when the kernel went from 2.6.38 to 3.0.anything, my machine would constantly randomly ...
0
votes
0answers
481 views

Ubuntu 10.04 Server w/ root on LVM2, Cannot boot after kernel update

I am running an Ubuntu 10.04 Server with root on a md raid 5 / LVM2 volume. After a kernel update, boot hangs at initramfs saying it gave up waiting for root, "ALERT! /dev/disk/by-uuid/##..## does ...
8
votes
2answers
725 views

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 ...
18
votes
3answers
35k views

Improving TCP performance over a gigabit network with lots of connections and high traffic of small packets

I’m trying to improve my TCP throughput over a “gigabit network with lots of connections and high traffic of small packets”. My server OS is Ubuntu 11.10 Server 64bit. There are about 50.000 (and ...
3
votes
1answer
81 views

What is the way to update /lib/modules after copying disk to a different system?

I have transferred the disk of a a Hardyvirtual machine to another virtual machine with a different kernel but there is no equivalent of /lib/modules// on disk. How can the /lib/modules of the new ...
1
vote
2answers
3k views

Upgrading linux-headers-server and linux-image-server fails

apt-get upgradetold me that packages linux-headers-server linux-image-server were kept back, and thus this answer lead me to run apt-get install linux-headers-server linux-image-server. However, the ...
2
votes
2answers
3k views

mkfs refuses to format device in the claim it's mounted when actually it is not

This is the problem: root@ip-10-126-247-82:~# mkfs.ext4 /dev/xvda3 mke2fs 1.41.14 (22-Dec-2010) /dev/xvda3 is mounted; will not make a filesystem here! And this is the debugging: ...
1
vote
2answers
2k views

task blocked for more than 120 seconds

I'm getting a lot of stuff like this on my ec2 instance: kernel: [141720.410047] INFO: task kjournald:14019 blocked for more than 120 seconds. kernel: [141720.410205] INFO: task flush-202:112:2005 ...
0
votes
2answers
4k views

error: “net.ipv4.netfilter.ip_conntrack_max” is an unknown key

I have a problem on Ubuntu 10.04.3 LTS x64 with sysctl net.ipv4.netfilter.ip_conntrack_max . If I run this command on shell, I get back an error: error: net.ipv4.netfilter.ip_conntrack_max" is an ...
11
votes
3answers
36k views

How to fix “BUG: soft lockup - CPU#0 stuck for 17163091968s”?

UPDATE: I updated the title of the message, because I've recently seen more of these problems with this exact time amount of 17163091968s. This should help people investigating the symptoms to find ...
3
votes
3answers
2k views

Maximum memory allocation for 32bit linux kernel

I was reading this article that talks about how maximum amount of ram dedicated for kernel usage in 32 bit windows is 2GB even when the total amount of ram is >4GB. ...
0
votes
1answer
614 views

Ubuntu kernel downgrade

Is there a way to downgrade Ubuntu kernel version by using apt-get package management tools? Is there Ubuntu repository with older kernel versions available? There are HW specific reasons I need to ...
9
votes
3answers
19k views

Soft limit vs Hard limit?

Can anyone explain in layman's terms what the difference between soft and hard limit is? Should I set my soft and hard limit to be the same? Or should soft be significantly lower? Does the system ...
2
votes
5answers
14k views

possible SYN flooding on port 80. Sending cookies

I recently had a server downtime. I looked everywhere and the only thing I found in my log files is: Feb 17 18:58:04 localhost kernel: possible SYN flooding on port 80. Sending cookies. Feb 17 ...
1
vote
1answer
465 views

Documentation on Kernel variables

I was wondering if some one can point to some good documentation which can give me detailed information about some kernel variable. I am right now mostly interested in the following variables / ...
3
votes
1answer
127 views

Ubuntu Server won't boot with “zip2: Compressed file ends unexpectedly” error

I am trying to boot lucid server on my new VPS but its giving me some problems. The boot gets to a point where it hangs. At this point it says: No such file `modules-2.6.31-20-server-amd64.tar.bz2' ...
4
votes
7answers
1k views

Linux freezes every few seconds

We're having an issue where one our Linux boxes (Ubuntu 10.04 LTS, running on EC2 with a quadruple-large size, 68GB of RAM and 8 virtual cores with 3.25GHz each) freezes up every few seconds. Typing ...
1
vote
1answer
363 views

Which Ubuntu 10.04 kernel should I use with Xen?

To run Ubuntu 10.04 32-bit and 64-bit servers under Citrix XenServer 5.6, which kernel should I use for the best performance? For new installations, can I specify that kernel in the boot option for ...
1
vote
4answers
1k views

Running out of LowMem with Ubuntu PAE Kernel and 32GB of RAM

I'm running a Java data import process on a 32-bit Ubuntu 10 PAE kernel machine. After running the process for a while, the oom-killer zaps my Java process. After some Googling and digging through ...
2
votes
2answers
3k views

VMWare tools on Ubuntu Server 10.10 kernel source problem

After install and running the vm-ware config, the config needs my kernel headers to compile some modules, ok, so I'll give it them, but it just won't work. It asks for the path of the directory of C ...
3
votes
2answers
3k views

Getty flooding syslog after kernel upgrade with “cannot open as standard input”

I just updated my kernel on an Ubuntu 9.10 system from 2.6.32.1 to 2.6.33.5, and everything seemed to go well, except now my system log is getting flooded with errors from getty: Jul 25 11:01:54 ...
1
vote
2answers
4k views

How to permanently disable a kernel module (kvm-intel) in Ubuntu 10.04?

Every time I start, I have to manually do "sudo modprobe -r kvm-intel" for VirtualBox to be able to use hardware virtualization facilities. How do I get rid of this?
1
vote
1answer
202 views

Boot Windows from USB disk with Ubuntu kernel and initrd

I have a situation where I have to boot using Ubuntu kernel and initrd first. Then check for attached USB/SCSI disk which has a Windows Installation and then boot Windows through USB/SCSI disk. I ...
4
votes
2answers
9k views

How do I upgrade the kernel in Ubuntu Server 10.04?

I'm running Ubuntu Server 10.04 LTS. When I login I see the message: 39 packages can be updated. 18 updates are security updates. The usual formula of sudo apt-get update sudo apt-get upgrade ...
3
votes
3answers
3k views

compile kernel 2.6.34 for Ubuntu Lucid for xen dom0 / pvops

I'd like to compile a recent Linux kernel (2.6.34) for my Ubuntu 10.04 Lucid Lynx AMD64 box, mainly because I'd like to use it as a dom0 kernel with the recent xen4. There's plenty documentation on ...
1
vote
5answers
1k views

VMware Tools in Ubuntu guest on VMware Server 2 do not build

When trying to build the VMware tools in my Ubuntu 9.10 64 bit guest on a VMware Server 2.0.2 host with Debian 5 I'm getting strange errors like: Building the vmmemctl module. Using 2.6.x kernel ...