Hello,
default in openSUSE 11.2 we have installed kernel-desktop. This kernel is optimized for the desktop.
What is the name of kernel optimized for server machine? In my case Firebird database + Apache + PHP?
Thanks.
kernel-default
Hi, I have find out that there are also
kernel-pae
This kernel supports up to 64GB of main memory. It requires Physical Addressing Extensions (PAE), which were introduced with the Pentium Pro processor. PAE is not only more physical address space but also important for the “no execute” feature which disables execution of code that is marked as non-executable. Therefore, the PAE kernel should be used on any systems that support it, regardless of the amount of main memory. Source Timestamp: 2009-10-26 15:49:03 +0100 GIT Revision: a3b45832d626d9c9646be88907aa3dabf0155894 GIT Branch: openSUSE-11.2
kernel-rt - The Real-Time Linux Kernel
This Kernel is for high-performance / low latency applications. Source Timestamp: 2009-09-03 21:06:06 +0200 GIT Revision: 0ce4ffd045cb8d47dea823c90e8471286b859653 GIT Branch: slert-devel
Maybe I should use kernel-rt?
pae kernel is only required on 32bit systems. If you’re running such, I suggest you switch over to 64bit if you want to use more than 4 gigs of RAM. pae degrades the more Ram you add and is suboptimal. PAE kernel is not for 64bit systems, if you have one
rt kernel is targeted at mission critical systems and embedded ones, where certain tasks must be guaranteed to finish within a set period of time. it doesn’t necessarily make it faster, since focus is most of the time on guaranteeing certain requirements for the applications
a lot of people keep forgetting this, but there’s a lot of real time stuff added to the mainline kernel over the years. Most rt patches make their way into the mainline kernel at some point
most servers care a lot about throughput and this is what kernel-default will shine on, since it doesn’t have preemptation turned on which can hurt throughput
very clear explanation.
Thanks!
The installer on 32bit would have selected -pae if the processors support it for the NX bit security.
The rt- kernel provides latency guarantees, mostly suited for professional audio & market trading like applications.
Not sure why a -pae kernel is offered on 64bit, it’s tempting to install it and compare the config file.
The kernel-default offers longer timeslices 250 Hz tick rather than 1000 Hz, as well as not enabling forced pre-emption of kernel code. That means multiple CPU intensive tasks, can get longer to run with ‘hot’ caches.
Does it even exist for the 64-bit arch? I don’t see one on the DVD.
It’s not - the arch is still i586 in the kernel - you can check it with zypper info kernel-pae on an x86_64 system.
I see it’s offering up the i586 package as available for install, presumably because zypper search finds it on an x86_64 box, and is willing to download it from the repo.
A succsesful install would likely lead to downgrade of glibc to 32 bit and then re-install to 32bits of all the x86_64 packages. Not good 
The reason it’s shown, is that no way was found to hide the i586 versions of kernel on x86_64.
Holiday greetings, lizard guild!
what is the major difference between the kernel-trace package and the rt package?
[QUOTE=robopensuse;2086588]The installer on 32bit would have selected -pae if the processors support it for the NX bit security.
I had installed opensuse 10 on a system and it immediately recognised the 8GB memory (in 32-bit system) When I installed Opensuse 11.1 it only recognised 3.25GB and I could not see a -pae version of the kernel available to me. How do I ensure I have the right download version to get a kernel that has -pae installed? Can I do some form of upgrade to my current 11.1 install, or should I try again with opensuse 11.2 ???
Mike
openSUSE 10 did not have the “split” kernel. PAE was still in the 32bit kernel. Don’t ask me why.
For the newer releases: yes, you should use the kernel-pae version. On 11.1 it is included. Just install it to replace your current kernel.
Installing 11.2 is a very good idea as well. IMHO it’s great, as a server, a workstation or a plain desktop.
[QUOTE=Knurpht;2099697]
For the newer releases: yes, you should use the kernel-pae version. On 11.1 it is included. Just install it to replace your current kernel.
QUOTE]
Thanks for the update. This explains why OpenSuse 10.x worked for me out of the box.
So, how do I ensure on the 32-bit version of Opensuse 11.x that I get the kernel-pae version? Is it an option during install? Is it an update once I get an installation going? or is it a different download?
Mike
You should see it in the software installer. It will pull in some more packages, like kernel modules.
You could also do this from the command line:
zypper in kernel-pae
Say yes to the rest of the packages zypper will want to install.