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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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 ...
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2answers
454 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 ...
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2answers
1k 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 ...
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1answer
661 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
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1answer
1k 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 ...
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4answers
117 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 ...
2
votes
1answer
1k 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; ...
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2answers
3k 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 ...
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2answers
122 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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1answer
389 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 ...
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4answers
154 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 ...
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1answer
134 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!
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1answer
67 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 ...
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1answer
6k 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
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1answer
125 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 ...
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2answers
1k 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 ...
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1answer
248 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
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1answer
1k 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
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2answers
150 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 ...
2
votes
1answer
2k 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
529 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
160 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
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1answer
183 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 ...
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1answer
64 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 ...
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2answers
508 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 ...
2
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1answer
119 views

High shmmax value in Redhat 6.3

We are using Redhat 6.3 with 30G RAM to host our Postgres server. The (default) shmmax value is 68,719,476,736 In some forums I have read that having an shmmax value larger than the RAM causes ...
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1answer
100 views

Multiple ethernet interface on one ethernet card

First I must say that I am new in linux and maybe I will ask trivial question. My job is to create 8 ethernet interface to be visible in kernel, but all of them should send and receive data through ...
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0answers
362 views

Xen hangs on boot when scrubbing RAM

I have a CentOS 5 server I can boot into the stock kernel just fine, but when I try kernel-xen, it gets stuck here: http://i.stack.imgur.com/wAI20.png When I try adding no-bootscrub to the kernel ...
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1answer
919 views

How can I diagnose and fix frequent 100% cpu utilization from kernel?

I have an Amazon EC2 micro instance running an old 2.6.16 kernel. It runs postfix, apache, and mysql. During normal loads, it's load average is around 0.05, and it runs this way 95% of the time or so. ...
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1answer
1k views

RHEL 6.0 upgrading kernel from 2.6.32-71.el6.x86_64 to 2.6.32-358.2.1.el6.x86_64

[root@localhost ~]# rpm -ivh kernel-2.6.32-358.2.1.el6.x86_64.rpm error: Failed dependencies: bfa-firmware < 3.0.3.1 conflicts with kernel-2.6.32-358.2.1.el6.x86_64 [root@localhost ~]# rpm ...
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2answers
364 views

“Never take kernel updates” — Any truth to this?

So I am having a discussion with a coworker today, and he let something out that I thought was bizarre, as I'm getting ready to apply security updates to one of our production servers. "You should ...
2
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2answers
2k views

Kernel 3.8, Apache2 with WSGI : INFO: task apache2 blocked for more than 120 seconds

We have upgraded our Kernel from 2.6.32 to 3.8.7 on a Debian system. We have a sharing with NFS to get the data for Apache2. And Nginx serves only static files as a proxy. Since we have installed the ...
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2answers
256 views

Check my Kernel for SELinux Support

I want to know if the kernel i am running has support for SELinux. What commands would i use to check this ?
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1answer
691 views

Adaptec RAID array was not detected after updating the kernel?

Continue from this topic, the newer kernel booted successfully but it doesn't see my sdc - which is a hardware RAID array (level 10). I'm sure the aacraid module is loaded: # grep aacraid ...
2
votes
1answer
938 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 ...
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2answers
420 views

Kernel Configuration, Which Processor family?

Which processor family should I use for the cpu shown below for the best fit?
1
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2answers
51 views

Debian Squeeze Kernel

I'm running Debian Squeeze completely up to date on a machine. However when running uname I see that I'm on a very old kernel: $ uname -r 2.6.32-5-amd64 Is this normal for Debian Squeeze? Should I ...
2
votes
2answers
486 views

Increase FD limitation then SSH not working?

I'm using CentOS 6.3 64bit, and having trouble with increase FD limitation: SSH not working after changed the limitation, every-times I logged on my server, after typed password, then "connection ...
1
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0answers
335 views

CentOS 6 won't load default (new) kernel, loads (another) older one instead

I am having a weird issue with a CentOS 6 system. I have upgraded the kernel twice now and when I reboot the system it still loads the older kernel. I also had a dc tech watch the screen as it ...
1
vote
1answer
156 views

Apache2 reload and System Crash

Reloading Apache2 caused Ubuntu 11.04 to Hang/Crash. Load average was 32 CPU Cores:8 Model: Intel xeon E5620 RAM:16 GB Kernel :2.6.38-13-generic Apr 6 09:05:11 406852 kernel: [3715446.033031] ...
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1answer
307 views

Is tcp_keepalive application dependant on Linux?

According to http://tldp.org/HOWTO/TCP-Keepalive-HOWTO/index.html , the kernel keepalive function occurs at the OS level, and doesn't require an application to explicitly call it. However I also read ...
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3answers
855 views

Compiling kernel version >= 2.6.34 on CentOS 5: RAID set “ddf1_foo” was not activated?

I want to mount a Ceph FS on some CentOS 5 servers. Since the ceph-fuse failed with below errors: # ceph-fuse --no-fuse-big-writes -m 192.168.2.15:6789 /mnt/ceph/ ceph-fuse[7528]: starting ceph ...
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2answers
1k views

Issue on yum update with kernel

--> Running transaction check ---> Package e2fsprogs-resize2fs-static.x86_64 0:1.42.3-3.el6.1.ovz will be installed ---> Package kernel.x86_64 0:2.6.32-358.2.1.el6 will be installed --> ...
3
votes
3answers
8k views

CentOS 6: strange page allocation failure messages [duplicate]

I set up a new Server with CentOS 6.4 final as successor for an old mysql server and I'm facing some problems with it. From time to time mysql connections are being disconnected. Furthermore the ...
0
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1answer
72 views

Compile Kernel Debian Squeeze

Am newbie, and I'm trying on Debian Squeeze to upgrade/compile kernel for problem I'm having with Linux-Vserver. The instructions I'm trying to use start with "apt-get installlinux-source-2.6.32" and ...
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2answers
1k views

Linux server resend SYN ACK

I am troubleshooting a connection timeout problem between two Linux boxes, where it seems the ACK to SYN-ACK was lost on the server's stack. The tcpdump is done on the server side. The client got ...
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2answers
3k views

CentOS 6 Xen guest fails to boot after 'yum update'. Kernel?

I Seem to be having an issue with a Xen guest not booting after a yum update. DomU Configuration: #kernel = '/boot/solus-vmlinuz' #ramdisk = '/boot/solus-initrd.img' bootloader = ...
3
votes
1answer
254 views

firewall output flooding dmesg

I log all dropped packets using following iptables rule: -A INPUT -j LOG --log-prefix "FW_DROP: " --log-level 7 and then in rsyslog.conf, I redirect this output to a separate file, so that my ...
0
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1answer
296 views

Effects of IW10 (initcwnd 10 initrwnd 10) on high speed LAN based TCP/IP communications?

What does changing the number of packets sent during the initial congestion window to 10 have on LAN connections? Via: ip route change default via GATEWAY dev INTERFACE initcwnd 10 initrwnd 10 Is ...
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0answers
334 views

UDP socket receive buffer size change on RHEL6.3

Our system used to work on RHEL5.3 And the socket receive buffer size is 64k. And that works fine. We can get message size up to 64k on UDP socket. But after system upgrade, it is running on RHEL6.3 ...