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.
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
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...
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!
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've got a dedicated server through Liquid Web. I can't say enough about how great the reliability and service has been since I switched over to them a number of months ago.
Nevertheless, with the advent of cloud hosting, I'm intrigued by the idea of paying for what I actually use on a server rather than having way more capacity than I need 90% of the day.
I've looked around here and there's a bit of talk about it but it doesn't seem like folks are scrambling into it and it also appears that the offereings are still relatively immature.
I really don't have the time to devote to tweaking, etc or figuring out something really complicated.
I'll stick to my dedicated server if it means tons of extra work or potential downtime or massive frustration but I wanted to get some feedback from the community about whether or not there are some stable cloud hosting options that are emerging that might be worth considering.
Windows 2003 IIS6 PHP 5.0.3 and PHP 5.2.1 running with the ISAPI dll MySQL 5.1.11
I kind of have 2 problems, the first being the one in the thread title and the second is while running any version of php my main site experiences slowdowns and hangs.
For some reason whenever I try to install a new version of PHP I have major problems. I have tried several times when new versions come out. I just recently tried the newest, 5.2.1, which I want to try and use, I think there are performance improvements for IIS and windows platform in the new 5.x versions?
Anyway I can install 5.2.1 and get it running, and my sites load, but soon after my main site starts to hang, stops loading or loads extremely slow. I can't figure it out. I even tried using the exact same PHP.ini settings from my old working php install.
So everytime I am forced to go back to the latest version that I know works with my server/sites, 5.0.3 [url]
If I restart IIS the pages start loading fast again right after, even recycling the worker process that the site uses usualy makes the pages load normal again.
I tried setting the worker process to recycle every 60min and to use 2 web gardens. These changes havn't really had any affect for better or worse.
Downgrading back to PHP 5.0.3 seems to run a bit more stable, but even with this version I get these slowdowns now. I have been running my site(s) on this server for 3 years now and most of the time they have ran stable.
I was sleeping this morning and recieved a text-message saying the site wasn't loading. So I wake up and the site indeed was pretty much not loading at all. I look at permon that I left running to see this: [url]
I give IIS a restart, which you can see above, then the levels go back to normal, here is a screen shot a couple minites later to what the "Current Connections" graph usualy looks like when the site loads fine. [url]
During this slowdown the CPU usage was not maxing out, was maybe averaging 60% and ram was 50%. I am getting a 2nd server soon to off-load the MySQL to it and have it dedicated for that. But i don't think that will help this current issue. Here is the system resources when the site is loading fine: [url]
I have around 40 or so other sites hosted on IIS and my main site "canadaka.net" which is purple on the top graph, is the only one that hangs or slowsdown. When this slowdown happens to this site, all the other sites on IIS, which are on a seperate worker process, continue to load fine.
I can't figure out why these slowdowns are happening.
Well haven't managed hosting on vps machines yes so I am wondering that how much this type of machine suit for running a hosting business ? Very honestly I think that people use vps for temporary bases and later they move to individual servers. I will appreciate your opinion.
Have run through a bunch of threads on mod_proxy race conditions, possible causes, and potential solutions.
What is the status? Is there a fix for this, maybe in 2.4.7?
On 2.4.3 in production we literally have 10K errors in the past 2 months along the lines of:
Code : AH00898: Error reading from remote server returned by...
Application server (JVM webapp) issues no errors at the time of mod_proxy error occurring. It seems then that mod_proxy is sporadically broken, which is horrible for end users accessing an otherwise rock solid production application.
Whats ur take on Wired Tree folks, shall i jump the ship and provide them with utter bunny mayhem (cause i am known to be intolerably insane when my server is down). How is their overall support, and network and performance ? Anyone current got "Server" from them who would like to throw some light on their performance and services ?