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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2answers
111 views

Does the initramfs image file need to be updated whenever grub.conf is modified?

I am trying to puzzle out a linux boot configuration problem involving legacy grub (0.97), LVM2, and dracut and trying to eliminate a few red herrings. My trial and error process goes like so: ...
1
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2answers
221 views

Best way to upgrade FreeBSD with non generic kernel (XENHVM)

Since manually upgrading from source (cvsup) is deprecated and the recommendation is to use freebsd-update: What's the best way to upgrade (e.g. 9.1 to 9.2) while keeping a non-generic (XENHVM) ...
0
votes
0answers
145 views

eth and bridge take very long time to set state on (debian 7 + intel i210 gigabit network controller)

It takes almost 5 minutes for eth link to get into state UP after reboot in debian 7 x64. The problem is those drivers are not in standard kernel, I had to install them from source (igb-5.0.6.tar.gz ...
2
votes
1answer
87 views

Idera ServerBackup / R1soft Kernel Modules

We currently have virtual (xen) servers from a host here in the UK and back up to an Idera R1Soft / ServerBackup system in the US. One of our servers absolutely refuses to compile the kernel module. ...
0
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3answers
176 views

Using Proxmox Kernel on Wheezy without proxmox system

I'm going to run two servers with OpenVZ on Wheezy. Since there are sadly no OpenVZ kernels in debian anymore I want to use the Proxmox kernel instead. I'm doing all replication with scripts I have ...
0
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0answers
65 views

Why does firehol generate an iptables ACCEPT rule on top?

Firehol generates iptables rules from a convenient configuration file. In my /etc/firehol/firehol.conf I have the following very simple configuration to allow incoming connections on http, https and ...
2
votes
1answer
59 views

How to tell which device in /dev a kernel module added?

I have just compiled the QLogic qla2xxx FC driver on a CentOS6.4 host, and done echo 'alias scsi_hostadapter qla2xxx' >> /etc/modprobe.d/modprobe.conf cd /boot cp initramfs-$(uname -r).img ...
0
votes
1answer
101 views

Server hangs after typing reboot command

I have a Debian Wheezy installation with Xen in kernel. All is fine but ... when I type a reboot command or shutdown -r now, my server is stuck and I see only that info on screen: INFO: task ...
5
votes
2answers
212 views

Optimal kernel configuration and patches for KVM host

I have a server (single socket Nehalem w/ 24GB RAM) acting primarily as a KVM host containing a bunch of Windows Servers and a few (tickless) Linux instances. I usually compile my desktop kernels ...
3
votes
1answer
150 views

What does nf_conntrack.acct really do?

I've found the kernel parameter nf_conntrack.acct interesting, in that the kernel documentation merely says "Enable connection tracking flow accounting". I've appended this to grub and rebooted and I ...
1
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0answers
158 views

FreeBSD XEN kernel not booting in XenServer 6.2

I have a XenServer 6.2 host, and I am trying to get a FreeBSD-9.1-i386 guest to run in PV mode. The installation of the guest is fine, but after a reboot with the new kernel the system does not boot. ...
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votes
2answers
310 views

Why “lsmod | wc -l” not equal “ls /sys/module | wc -l”

Why do these two commands return different results? lsmod | wc -l 100 ls /sys/module | wc -l 138
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votes
1answer
1k views

Unexpectedly shrunk window

I run a major media upload/download site and I noticed these: Is this serious or background noise due to the big file sizes and is there any tweaks I can add to /etc/sysctl.conf to improve and ...
1
vote
1answer
89 views

What is the purpose of /proc/config.gz

Please what is the purpose of the /proc/config.gz file in my Linux server filesystem? Is it some backup file, or it is an updated file by the Linux system? Can I change it?
0
votes
0answers
790 views

How to install ip_gre when Module ip_gre not found

please how to install ip_gre module into kernel when module not found? modprobe ip_gre FATAL: Could not load /lib/modules/3.10.9-xxxx-grs-ipv6-64/modules.dep: No such file or directory make ...
1
vote
3answers
273 views

High CPU usage in random IP/Port UDP DDoS

I have been getting these UDP floods with random IPs and ports. randomip:randomport -> myip:randomport 0 byte payload For some reason it is using a lot of CPU. Here is the results of perf top -e ...
0
votes
1answer
206 views

What kernel module to compile for getting QOS service on Linux

We are developing on Linux system whose kernel had been compiled without QOS service years ago. Currently we want the QOS service back and plan to compile only the QOS-related kernel modules and ...
0
votes
1answer
66 views

Open the Linux QOS Service dynamically

We are developing a C++ application on Fedora (of kernel 2.6.9). This application will use the Linux TC utility to limit the bandwidth of specific applications by scanning their ports and setting ...
0
votes
1answer
126 views

Linux kernel option to force video card to stay on

I just installed Debian Wheezy 7.1.0 on an Intel vPro System (Intel Core i5-2520M, SuperMicro MBD-X9SCV-Q-O). Intel AMT's KVM works perfectly until Debian has completed booting and shows the login ...
2
votes
0answers
85 views

Redhat 6.4 configured to log Martian packets but is not logging ll header

I am trying to investigate the source of martian packets I have been seeing on several servers connected to the same subnet. The logging of martian packets has been enabled in /etc/sysctl.conf. ...
0
votes
1answer
73 views

Xen: what are domU kernel config requirements for live migration?

We recently added iSCSI storage to two Xen servers running a mix of Gentoo and Ubuntu 10.04 and 12.04 domUs. When trying out live migration of domU I found that I can migrate just fine the Ubuntu ones ...
0
votes
2answers
70 views

continous kernel EIP errors

I am getting the following error time to time. Process is different at each time. What do you think about the error? What do you suggest? Kernel is Linux version 3.5.3 (developer@devel) (gcc ...
0
votes
0answers
225 views

module scsi_wait_scan not found boot kernel panic after kernel update

I got troubles booting after kernel update: After upgrading kernel 3.10.4-1 to 3.10.5-1 or 3.10.6-1 the system is refusing to boot with module scsi_wait_scan not found error message. Then comes ...
1
vote
1answer
94 views

Slackware 10.1 hangs at boot with kernel 3.x

In Slackware 10.1, what happens between rc.S and rc.M during boot? Trying to boot kernel 3.x (tried 3.4 and 3.10) on this box and it hangs right after rc.S finishes execution. 2.6 kernels boot up just ...
0
votes
1answer
44 views

forcing linux kernel 3 to recognize cdrom as hdX

I have a problem with older version of anaconda linux installer. I have upgraded kernel in my distro, however, when this anaconda boot with this 3.4.52 kernel, can NOT find cdrom. As far as I ...
0
votes
2answers
135 views

Moving a process to and from swap [closed]

I've got serveral processes (game servers) on my linux server that use up 50MB of RAM. They are not constantly being used, and I'd like to be able to run more instances than my RAM capacity allows. I ...
0
votes
2answers
618 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
205 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
1answer
501 views

Kernel parameters mem and dom0_mem in XenServer 6.1

We are running XenServer 6.1 in production, and recently had OOM-killer fire and eventually take down one of our blades. I noticed that in the kernel logs from the oom-killer instance that it seemed ...
0
votes
4answers
99 views

Can 3.2 kernel KVM VMs run in a 2.6 kernel host

So I got a Redhat6.2 and going to install it on a new IBM x3650 m4 server. However I want use Debian because I'm more familier with it. Since x3650 doesn't support Debian(I've tried but no luck), I ...
0
votes
1answer
191 views

Error setting capabilities, capability management disabled;

root@monitor:/opt/observium# service syslog-ng restart Stopping system logging: syslog-ng. Starting system logging: syslog-ngsyslog-ng: Error setting capabilities, capability management disabled; ...
1
vote
2answers
706 views

Disable ICMP Unreachable replies

I am using a Debian 6 - 64bit OS and my server is ddosed/flooded through udp protocol from time to time. I basically host game-servers and my firewall is set to rate-limit the packets on allowed ports ...
1
vote
2answers
100 views

How do I make OOM Killer more passive

I am able to compile a program with 1 GiB RAM on a VPS using old 2.6.x kernel. But when I tried to compile it on a VPS with 1.1 GiB RAM and 3.9.x kernel, the compiler always killed by OOM Killer. How ...
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votes
1answer
217 views

Where to find source of an Amazon EC2 compatible kernel

I have some issues with finding the source code of Amazon EC2 compatible kernels. There is a tutorial in Amazon EC2 documentation of how to run instances with custom kernels, but those must be from ...
0
votes
4answers
140 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 ...
0
votes
1answer
78 views

Pass kernel boot parameters from dhcpd.conf for a host group?

Is it possible to configure dhcpd.conf such that a specific host group would use an additional kernel boot parameter passed on to the kernel loading? Thanks!
1
vote
1answer
33 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
1answer
2k views

Testifying rasing net.core.somaxconn can make a difference

I got into an argument on the net.core.somaxconn parameter: I was told that it will not make any difference if we change the default 128. I believed this might be enough proof: "If the backlog ...
3
votes
1answer
77 views

IPSEC AES key length in kernel 3.9.3

I have a working ipsec-tools configuration which uses aes-ctr encryption with 224-bit key (192bit for key+32bit for nonce). Everything works well on 3.2.0 kernel. Here's what man setkey says about ...
1
vote
2answers
784 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
0answers
116 views

Proxmox 3.0 installation on any VPS

I have an account on digitialocean.com I create a droplet debian wheezy. I installed proxmox 3.0 manually via command line. At the end of installation I restarted the server but again it uses default ...
2
votes
1answer
412 views

Kernel oops on Linux running in VirtualBox breaks some IO-related functionality on the server

We are having problems with CentOS release 6.3 running in VirtualBox on Windows 7 machines. The symptoms are the following: Everything works as normal for several hours, even days. Then something ...
2
votes
2answers
98 views

How to get a kernel panic count [closed]

Is there any way to check the number of kernel panic that happened on a system ? If not, any idea on how to do make this new functionality ? I would like to hear about an answer for most Unix-like ...
1
vote
1answer
392 views

What does this kernel error mean and how should I respond?

The following except is taken from the logwatch of a production LAMP web server I'm about to inherit. It is a dedicated Dell server running CentOS 5 with RAID 1 across two 1TB drives. I have little ...
7
votes
3answers
297 views

Enable SMP on Debian i386?

I've been running a couple old HP machines on Debian for a while, and only recently noticed that they were only 'recognizing' and using one processor. cat /proc/cpuinfo only shows output for processor ...
0
votes
1answer
76 views

Fuse module for s3fs

I am trying to install the s3fs software. I however keep coming upon this error: $ sudo /usr/bin/s3fs bucketname /mnt fuse: device not found, try 'modprobe fuse' first $ modprobe fuse FATAL: Module ...
0
votes
0answers
147 views

Kernel update on Xen CentOS

Running a "yum update", CentOS try to install a new kernel. However, I get this: Installing : kernel-2.6.32-358.6.2.el6.x86_64 1/1 grubby fatal error: unable to find a suitable template ...
0
votes
0answers
116 views

task httpd blocked for more than 120 seconds

I know it exists a lot of threads about this problem, but nowhere can I read how I can find ut what the problem should be. Here our configuration: We have 3 apache-webserver on a Hyper-V 2012 server. ...
0
votes
1answer
98 views

Wndows Azure: “Linux Integration Services for Hyper-V has been removed.”

When I am trying to yum update my centos in Windows Azure, the following appeared Linux Integration Services for Hyper-V has been removed. Please reboot your system. So I reboot it. But ...
0
votes
1answer
48 views

How to update/maintain a patched kernel?

If I patch my linux kernel with grsecurity, will I still be able to update my system with yum (or apt-get)? Won't the updates available via yum be incompatible with my patched "non standard" version ...