Centos + Kernel 2.6.9-34.0.2- How To Upgrade Kernel
Apr 29, 2007
Last year I ordered a new server with Centos 4.3 and it had the kernel kernel 2.6.9-34.0.2ELsmp installed. It runned fine and I didn't update any packages since then.
Today I started getting a problem where both mysqld and kswapd0 uses very high amounts of CPU, spiking up to 100% and my memory usage is at 99% all the time. The problem seems exactly the same as the one mentioned in this thread.
In that thread the exact same kernel is said to be insecure and to cause this problem. I also came across a centOS bug that reports this problem with high cpu, mem usage and mysql & kswapd0 consuming all resources.
In the linked thread the person solved the problem by upgrading to kernel 2.6.9-42 using rpms but others recommended a newer kernel or a custom compiled kernel for CentOS.
Apparently when they used yum it said 34.0.2 was the latest kernel.
What should I do to upgrade the kernel, which version should i upgrade to, and where do I get it from? I won't be able to compile a custom kernel and I've only installed basic rpm packages before.
My current kernel version is "2.6.9-42.0.10.ELsmp #1 SMP Fri Feb 16 17:17:21 EST 2007 i686 athlon i386 GNU/Linux". I want it to be upgraded since it is old. I have been told by our server management company that the latest kernel distributed from yum is kernel.i686 0:2.6.9-78.0.22.E. Can anyone tell me if this version is safe and secure enough? It is a CentOS release 4.7 (Final) server with cPanel installed.
I'm going to add a second AMD opteron 270 dual core processor + 2 GB DDR ram to my server this week, but do i have to recompile the kernel after i've installed the second processor? Or change something in grub?
setup: 1 X AMD dual core opteron 270 ( + 1 X AMD dual core opteron 270 ) 2 X 1 GB DDR ECC registered ( + 1 X 2 GB DDR ECC registered) Tyan thunder 8kse motherboard # uname -a Linux srv01.xx*********** 2.6.16.17 #1 SMP Mon May 22 04:13:34 EDT 2006 x86_64 x86_64 x86_64 GNU/Linux
We upgraded our kernel 2.6 based servers in the network, one of them didnt came back online after rebooting the system, it seems that the network module cant be loaded.
[root@server.hostname.com:~]/etc/init.d/network start Configuring.. : [ OK ] Activating ... loopback: [ OK ] Activating... eth0: device tg3 eth0 does not seem to be present, delaying initialization [FAILED]
I tried booting with older kernels but the error stills
I have a server running Fedora 4 and WHM/cPanel. I would like to upgrade the linux kernel to the latest version, so mosey in via SSH and type "yum -y upgrade". It downloads a few things and tells me everything is hunky dory.
Now, the version it says it is currently running is: 2.6.17-1.2142_FC4 #1 Tue Jul 11 22:41:14 EDT 2006
Is that the really the newest version available? Maybe I'm confused as to how this works, but if I go to kernel.org it tells me the most recent stable version of the kernel is 2.6.24.3. Is this because I am running FC4?
i have a 32bit centos running with 8 gigs, but only 7 is registering when i contacted support they told me
Your server does in fact have 8GB of physical memory however the reason it is not being recognized is due to the fact that you are using a 32 bit operating system. By default, the 8GB would be recognized if it were a 64 bit OS however on a 32 bit operating system, you must install and boot into the PAE kernel (physical address extension) for the 8GB to be recognized and utilized. The PAE kernel can be installed through yum when connected to your server as root over SSH. Once you have installed the kernel, you will need to reboot the server for these changes to take effect
i tried
yum pae install
yum pae kernel install
both didnt work can anyone give me a quick step by step guide on how to go about this.
I was wondering how I would go about ensuring my kernel is up to date on my vps. I am running centos and I have cpanel, so I am not sure if there is anything special that has to be done or avoided when running cpanel.
(The box, 2 years now, never had issues before all you will read...)
I do have a box at the IP xxx.xxx.xxx.xxx, which on 15th Nov. was: AMD 4200+ with 300 GB hdd for OS, and CentOS 4.5 on it...
Because the system was facing few load problems of wrong installed applications, we decided to do a fresh OS reload to the latest OS version and cPanel.
on 16th Nov, the box was up and running with CentOS 5, and cPanel 11.
the kernel is: 2.6.18-8.1.15.el5
After few hrs the box was done and IO restored all backups in it anbd all worked fine, I realized that I couldnt access cPanel, page was blank for everything.
Also, most pages (except simple html) where showing internal error 500.
I did a reboot. probelm was fixed.
After few hrs, problem came up again...
I left ssh logged in to see whats wrong.
I found out that every few hrs, that issue was happening:
Message from syslogd@server at Sun Nov 16 11:47:21 2007 ... server kernel: journal commit I/O error
Then, we had techs to check HDD for errors. they did fsck, and said disk has to be replaced (at this point, without wanting to offend anyone, I have to state that 90% of techs in datacenters, or at least at mine --won't name them, 99% you guess which DC it is...-- are just low paid students that don't know SIMPLE things...) so we told them to replace the HDD and do OS reload in new drive...
So, on 17th Nov. we had online a new HDD, 400 GB with CentOS 5 loaded in it, and cPanel 11...
After few hrs and all working and backups recovered, the issue came up again!
This time, with exactly same error, techs told us it may be RAM, so they replaced the RAM and we waited...
In 2,5 hrs, bang, it happens again, same error.
They say, it might be the sata cable...
we replace it...
AGAIN ERROR.
we ask them to loook at it seriously, and after lot pressure, to avoid case that mo/bo or controller is wrong, they do upgrade us in a BRAND NEW colocated box, which was this time: Intel Core 2 DUO, 6300, with brand new 500 GB HDD and new RAM.
We recover in the new box the backups.
Box is online today at 18th Nov...
and the issue comes up again!
Message from syslogd@server at Sun Nov 18 11:47:21 2007 ... server kernel: journal commit I/O error
I ask them what the **** is going on now and why after having all hardware replaced with new, and all OS reinstalled clean on new drives and new devices, 3 times, why we have again the same error...
And their response: power cable was loose, we replaced power cable...
Guys, sorry, this is really DUMP... loose cable cannot give that error...
and the error... continues!
Also, at this point, I have to let you know, that when this error comes up, (Message from syslogd@server at Sun Nov 18 11:47:21 2007 ...
server kernel: journal commit I/O error) the filesystem becomes READ-ONLY and nothing gets affected, if we do a cold reboot by reset button, it comes up again and all work PERFECT, until the issue comes back again.....
I am desperate with that, let me know what I have to do!
we have one box in hivelocity.net that has been down so many times this month that we were forced to remove links to siteuptime where we were once so proud of having a 99.7% uptime for 3 years in theplanet.
syslog shows that just before crashing, these entries were made:
kernel: kernel BUG at mm/rmap.c:479 kernel: invalid operand:0000 [#1]
dmesg also shows this:
... Brought up 2 CPUs zapping low mappings. checking if image is initramfs... it is Freeing initrd memory: 482k freed NET: Registered protocol family 16 PCI: PCI BIOS revision 2.10 entry at 0xf9f20, last bus=1 PCI: Using configuration type 1 mtrr: v2.0 (20020519) mtrr: your CPUs had inconsistent fixed MTRR settings mtrr: probably your BIOS does not setup all CPUs. mtrr: corrected configuration. ...
i've googled these messages and they point to ram problems.
hivelocity.net claims to have done diagnostics on the box and that there were no problems reported.
they said this is a result of a sys configuration problem made by us.
Just to make things clear, i am not new at setting up VPS nodes, i have set up all of my servers with the HyperVM/OpenVZ setup and they work perfectly, but im having a problem with a new server.
Just received my new server, installed HyperVM-Slave, rebooted but the OpenVZ kernel was not installed for some reason, so i manually installed the OpenVZ Kernel using the RPM as yum seemed to install the wrong kernel.
I then installed the kernel using RPM and got this error at the end of installation:
grubby: unable to open /dev/hda: No such file or directory grubby: unable to open /boot/boot.b: No such file or directory grubby fatal error: unable to find a suitable template
I have never encountered this error with any of my other servers before...
Also after installation everything seems to be correct. /etc/grub.conf has the new OpenVZ kernel displayed, and default is set to 0, so upon startup it should be booting the correct kernel, but the thing is, when i reboot the machine the default kernel is loaded even though the grub.conf is configured to load the OpenVZ Kernel.
Im thinking that this may be due to the error i got when installing the kernel.
I'm not sure if anyone else has come across this but I'm sure you are all aware that CentOS 5.3 default kernel comes with realtek support.
But the default realtek drivers have a bug in them when it slows down upload and downloads drastically and shows ping times above 2000+ ms in the same datacenter.
A fix for this is simply upgrading the kernel to the latest version available (2.6.29) with realtek driver support.
I tried to 'google' they to find the solution, but now i still not find out ... I'll try to reload OS. After reload OS, if i dont have floppy disk, how can i update kernel with no error?
here is what I seen when I installed kernel-2.6.20-1.2948.fc6.src.rpm
rpm -ivh kernel-2.6.20-1.2948.fc6.src.rpm 1:kernel warning: user brewbuilder does not exist - using root warning: group brewbuilder does not exist - using root warning: user brewbuilder does not exist - using root ########################################### [100%] warning: user brewbuilder does not exist - using root warning: group brewbuilder does not exist - using root
then when I ran: rpmbuild -bp --target=$(uname -m) /usr/src/redhat/SPECS/kernel-2.6.spec
I seen this error: + Arch=x86_64 + make ARCH=x86_64 nonint_oldconfig In file included from /usr/include/sys/socket.h:35, from /usr/include/netinet/in.h:24, from /usr/include/arpa/inet.h:23, from scripts/basic/fixdep.c:117: /usr/include/bits/socket.h:310:24: error: asm/socket.h: No such file or directory make[1]: *** [scripts/basic/fixdep] Error 1 make: *** [scripts_basic] Error 2 error: Bad exit status from /var/tmp/rpm-tmp.93770 (%prep)
I need to have this installed to get a app installed etc... suggestions or ideas? thanks
I have a Xen VPS. I started with a Debian 4 image and have since upgraded to Debian 5. Firstly was this advisable? Secondly what Kernel version should I be running, or rather is it set by my installation or by the Xen server?
as part of a project I have lately been looking into various aspects of kernel tuning. Most notably lately tuning the TCP stack for more efficient memory usage/throughput.
Thought I would start this thread to mention some of the tools I'd found for doing testing and see what anyone else had to recommend.
So far my favorite of the bunch is nuttcp. Its easy to use and gives a very good idea of how much of your bandwidth you are able to utilize.
A few interesting web pages are as follows for anyone interested in the topic:
[url]- Tuning TCP for High Bandwidth Delay networks
[url]- TCP Tuning Cook book, some interesting information in there as well
[url]...formanceTuning - Performance Tuning TWiki. Has a list of useful tools, flags for existing tools and ways to monitor network performance from a system level, along with some suggestions of things to correct
What is the best way to find out which filesystems and harddrive drivers you can remove? Obviously, i need ext2,3 but how do you find which HD you only need?
