In computing, the kernel is the main component of most computer operating systems; it is a bridge between applications and the actual data processing done at the hardware level. The kernel's responsibilities include managing the system's resources (the communication between hardware and software ...

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19 views

insert module to kernel [migrated]

I installed latest version of IPCOP, I've the correct module of my wireless card (htc_9271.fw): put it to /lib/firmware/ there is not any insmod/rmmod but only modprobe: modprobe htc_9271 FATAL: ...
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25 views

Getting segmentation fault when giving input to structure members on run time [migrated]

I have written a small code to fetch info of 'n' number of students. But after running the program, I'm getting a segfault. Please find the code below. struct students { char name[20]; int ...
2
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1answer
39 views

Use VPS provider's kernel or maintain my own?

I've got a Debian Wheezy VM on Linode and they run it with their own kernel. As a reputable company, I'm sure they're quick to apply security patches, and all I need to do is reboot to get the new ...
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0answers
41 views

Upgrading CentOS from 6 to 7 has broken my boot sequence

I ran the upgrade assistant provided by CentOS for upgrading from CentOS 6 to 7. The upgrade appeared to have been a success, however my system now hangs when trying to boot up. (Keep in mind I have ...
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1answer
43 views

New linux with old kernel in chroot [closed]

I have access to enterprise level server, but it have kernel version Description: Red Hat Enterprise Linux Server release 6.4 (Santiago) Release: 6.4 Codename: Santiago ...
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0answers
19 views

How to find what is causing a Kernel EventTracing error in the Event Log?

I am troubleshooting a Kernel EventTracing: "session failed to start with the following error: 0xc0000011" that pops up too many times in my event log. Every solutions I found in google were very ...
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1answer
22 views

Enable IP forwarding inside an OpenVZ container but disable it on host

Is it possible to enable IP forwarding inside an OpenVZ container but keep it disabled in host system? I understand that OpenVZ containers and host share kernels, but I can use sysctl to set ...
2
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0answers
38 views

BUG message on xenserver 6.5 - bad memory?

Several times a day I receive the following error in /var/log/messages. The server hangs and requires a reboot to respond again: Feb 1 13:44:54 xenserver-abfuqvrs kernel: [35023.166776] BUG: unable ...
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1answer
19 views

What does the tcp_fastretrans_alert error mean?

I found this error a couple of times in /var/log/messages after experiencing some odd TCP behavior: For some reason, if I connect to for example SSH for the first time in say an hour, the connection ...
0
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1answer
46 views

Which is the physical device behind the logical /dev/___ device

From time to time I get myself dealing with this same problem: from a linux logical block device (something below /dev/), I need to find the actual hardware behind it (something probably being listed ...
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0answers
27 views

make linux kernel read swap back into memory [closed]

Occasionally, I run a script that uses the majority of the 16GB of physical memory on my workstation. The kernel then swaps out the rest to swap partitions on multiple disks. After the script is ...
3
votes
1answer
495 views

VMWare ESXi error upon boot “Relocating modules and starting up the kernel”

Coming back from a 4-day weekend, I noticed the A/C had been turned off for the duration of the long weekend and the heat was around 80-82 degrees. The HP ProLiant DL185G5 was running but the system ...
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1answer
41 views

Influence of kernel code execution to Load average in top?

I'm trying to tests the amount of CPU that iptables use for NAT. Perhaps it will be more accurate to say "the amount of CPU that the netfilter kernel module" uses. The approach i took was to try and ...
3
votes
1answer
42 views

How to keep specific old kernels around after a yum update

I know that in CentOS 6.x, you can put the following line in /etc/yum.conf which tells yum to keep the last N kernels (by default this is set to five): installonly_limit=5 However, there are cases ...
15
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2answers
242 views

Does the “bs” option in “dd” really improve the speed?

Every now and then, I'm told that to increase the speed of a "dd" I should carefully choose a proper "block size". Even here, on ServerFault, someone else wrote that "...the optimum block size is ...
1
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1answer
27 views

Kernel dependency error on Ubuntu 12 server

I was doing my quarterly updates of an Ubuntu 12 server. After an apt-get update succeeded I'm getting this error running apt-get anything. Depends: linux-image-server (= 3.2.0.72.86) but it is not ...
0
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0answers
27 views

How does a kernel patch propagate into distribution updates?

I have been affected by, and helped to debug, a kernel bug. A patch has been created by the maintainer of the module, and submitted. I am interested to know how the patch propagates through to binary ...
4
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3answers
168 views

Modifying kernel cmdline in Ubuntu

I have a number of systems on which I need to modify the kernel cmdline, adding a few options. At the moment I do it using the following procedure: Open /etc/default/grub Modify ...
2
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0answers
638 views

OpenVPN ERROR: could not insert 'tun': Unknown symbol in module, or unknown parameter (see dmesg)

I'm trying to configure OpenVPN on my Debian 7 VPN but I'm getting the following error ERROR: could not insert 'tun': Unknown symbol in module, or unknown parameter (see dmesg) I tried the ...
1
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1answer
99 views

dspam crashes with “general protection” kernel error [closed]

I use DSpam with Postfix. Recently DSpam started to crash with the following error in syslog: Nov 16 14:10:55 home kernel: [ 133.042190] traps: dspam[1692] general protection ip:7f63a493f3b0 ...
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1answer
51 views

General protection fault by __d_drop following SMTP attack

The SMTP port (Postfix) of my box running 3.16.5 is being hammered. The log repeats this over and over: Nov 14 09:16:25 [postfix/smtpd] lost connection after UNKNOWN from unknown[177.43.41.74] Nov 14 ...
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1answer
62 views

Solaris kernel parameter equivalence to Linux

I have set the following tcp kernel parameters in Solaris ndd -set /dev/tcp tcp_ip_abort_interval 120000 ndd -set /dev/tcp tcp_rexmit_interval_max 15000 ndd -set /dev/tcp tcp_rexmit_interval_min ...
0
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3answers
79 views

Why I should prevent yum from update kerneI?

I was googling about yum and reading some articles when I stumbled on bunch of articles about disabling yum from update kernel packages. Now I'm wondering why I should do that. When I update system I ...
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0answers
12 views

EXSI4.0. 2 different kernels - one boots other locks up immediately, how to check initrd difference

I have a ESXI4.0.0 (v4) host, where I am trying to install a guest. The host machine is a regular Intel PC. I have 2 different ISO images (heavily modified version of SLES for a commercial product), ...
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3answers
100 views

delete millions of files within a directory [duplicate]

The other day I ran bleachbit on my system. I had enabled wipe disk space option in it. It took several hours and my disk space filled up completely (100GB or so). After waiting forever, I decided to ...
0
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0answers
102 views

How will updating kernel affect everything else?

I'm new to Linux and I'd like to try to upgrade kernel on my little NAS, but I don't really know how it will affect installed packages and user files, and do I really need to upgrade it? Plus the ...
1
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1answer
331 views

Command apt-get -t wheezy-backports install linux-image-amd64

I have a server with Debian wheezy and kernel vmlinuz-3.2.0-4-amd64, hosted at OVH. I would like to upgrade the kernel. Normally at ovh, you can find some kernel already configured. but the files I ...
3
votes
1answer
94 views

Linux Network tuning to prevent tcp rcvpruned and backlogdrop?

My datanodes in my hbase cluster are triggering some tcp rcvpruned and backlog drops from time to time: It seems to be there are at least two angles to approach this at: Tune HBase/HDFS etc... so ...
0
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1answer
493 views

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: ...
1
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1answer
316 views

What is the unit of “mem” and “memory” in /proc/net/sockstat

What is the unit of mem and memory in /proc/net/sockstat? Bytes, KBytes, Pages? [kbrandt@ny-kbrandt01: ~] cat /proc/net/sockstat sockets: used 153 TCP: inuse 7 orphan 0 tw 0 alloc 8 mem 1 UDP: inuse ...
2
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1answer
213 views

CPU error messages shown in console during boot — “CPU1: Stuck ??”

I recently installed a second CPU into a server. The CPU is identical to the first and I verified that the CPU is in good working order prior to the installation. The server booted up and I installed ...
0
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0answers
173 views

Strange memory usage behavior in GlusterFS machines

I'm running into a strange high memory usage problem in my environment. I have a two GlusteFS nodes that are serving 26 replicated volumes. Each morning, both servers will consume the majority of all ...
0
votes
1answer
65 views

Upgrading Linux kernel module without reboot

Is there any way to upgrade linux driver module without rebooting the system ?
2
votes
3answers
2k views

CentOS 6.5 new Kernel not active after reboot

Today I was running some yum updates and wanted to verify that everything went through fine by making sure I had a new kernel. To my surprise I noticed that CentOS was still running ...
1
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1answer
397 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?
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2answers
297 views

CentOS 6 - Kernel 3 from CentOS 7 Repo?

i want to run kernel 3 on centos 6. I found out, that it cant get installed over yum and i would need to compile it by my own. My question: Could i use the centos 7 repo to install kernel 3.x from ...
1
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2answers
58 views

When a socket switch to TIME_WAIT state, why I can't see its inode number?

I'm developing a program in python that parses /proc/net/tcp informations, but unfortunately, while I was doing this, I saw a strange thing. Practically, when a socket change in TIME_WAIT state, ...
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votes
2answers
202 views

Can you use CGroups inside an OpenVZ Container?

just a quick question, which i have had trouble finding the answer to: The OpenVZ Authors have been contributing a large amount of code to the linux kernel, in order to get virtualization features ...
0
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0answers
236 views

Nodes crash with kernel panic due to some bugs in autofs4 module

Recently, my computing nodes started to crash very often. In a pool of ~100 nodes running Ubuntu 12.04 for scientific computing, a machine dies every hour with the following kernel panic message: ...
3
votes
3answers
2k 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
126 views

Verify architecture of kernel file

Note: I am NOT interested in the currently running kernel, but on a kernel that I am going to boot and which is in a file in the filesystem. I am going to boot a new kernel. I have prepared grub.conf ...
2
votes
1answer
136 views

Kernel Compile crashing on Hyper-V due to memory issues

This is on a Hyper-V machine. I've set the min RAM to 512 and the max to 2048. The host machine has more then enough RAM. Does Linux have an issue with Dynamic RAM on Hyper-V? I can't seem to ...
1
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0answers
298 views

OpenVZ - updating kernel and all containers

Last night I upgraded to the latest kernel of openvz. I rebooted the host node. It came up with the latest kernel. However, the containers are still running the old kernel. What I did on the host ...
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votes
1answer
24 views

Is there anyway to specify the version of kernel update with apt-get? Debian 7 [closed]

Is possible to select the version of Kernel I need in apt-get? Actually, I need to update it but I had lot of configurations problems with 3.2. Or the only way is compiling the kernel? Thank you
2
votes
1answer
188 views

Linux read disk cache and NFS

I am interested in the impact of the read disk cache on accessing a file through NFS. Lets say I have a file on NFS. I access it (do "cat myfile") from a linux host "A". If there's enough RAM a file ...
1
vote
2answers
680 views

grub.conf missing initrd path after kernel update

I updated a server this morning and the latest kernel panics during boot. Upon review of the grub.conf file I found the initrd path was missing. Is there a way to fix this issue? Or should I remove ...
1
vote
3answers
942 views

Error installing new OpenVZ kernel

Seem to have an error when updating the kernel on a OpenVZ server when running "yum update" im getting the below Loaded plugins: fastestmirror Loading mirror speeds from cached hostfile * base: ...
0
votes
1answer
93 views

FTP server suddenly down

Suddenly I can not use anymore my FTP server and I get via ssh the following kernel report. I'm running on Debian 7.0 with ISPconfig3 kernel:[801112.466009] nf_ct_ftp: dropping packetIN= OUT=venet0 ...
1
vote
1answer
190 views

CentOS only detecting 50% of ram on IBM Server

I have IBM server with 16 GB RAM installed. Initially it showed 16 GB with free | grep Mem | awk '{print $2}' but now it shows only 8116136 but it must show 16439208 When I do dmidecode ...
10
votes
1answer
4k views

How does vm.overcommit_memory work?

When I use the default settings: vm.overcommit_memory = 0 vm.overcommit_ratio = 50 I can read these values from /proc/meminfo file: CommitLimit: 2609604 kB Committed_AS: 1579976 kB But ...