I've got an IBM intellistation Mpro with a PII 400. This is a dual processor machine and I want to exploit that. I'm just wondering if there are any known issues with dual processing or any processor in general. Any reason to avoid AMD? looking for a Dual 800 or dual 1g setup.

And how do you setup linux for dual processors?
I'm running RH8 now but will likely switch to Mandrake 9

thanks

I run duel p3 600mhz.
There is absolutely nothing wrong with Duel processors and Linux...on the contrary...there is everything good about Linux and duel processing.
All you need to set it up, is get your duel CPU motherboard, your two cpu's, and voila!,
No reasons to avoid AMD either...except I'm just so used to Intel that I don't even think about it and always buy Intel.
I am aware, however, that AMD is cheaper, so suit yourself,

So, welcome to the SMP club, , you'll be greatful you got SMP,

any other questions, just fire them up,

zLinuxz

You will need to recompile your kernel to enable smp

not if you install it outta the box, or if you install kernels 2.4.17+, all have SMP enabled as Default.

That's true if both processors are installed when the OS is installed.
If the processor is added to an existing OS, the bios will recognize it but linux won't. At least that's how it worked for me using rh7.2, you can check /proc/cpuinfo to see if both processors have been detected.

RH 7.2 comes with kernel 2.4.7 I believe...however, if you are a person that likes to keep his/her things updated...you shouldn't have anything less than 2.4.19 in your linux box. If that is the case...SMP is enabled by default, it doesn' tmatter if you install a new motherboard and put 2 processors in...linux will recognize it at boot up. Automagically.

Makes sense. I've haven't installed a "newer" kernel from scratch. I had redhat 7.2 with kernel 2.4.7 with one processor. When I added the 2nd processor I upgraded to 2.4.19 and chose my own options which included smp, it wasn't a new install.

yeah, it's cool bro. I like to always install a Vanilla kernel. I never use Redhat kernels...they always conflict with my hardware...so gotta do all the installs by myself,
However, I like redhat's distro...the install is very nice, and it's not that kid distro like persay Mandy...anyway
glad to talk to you,

I see lots of times people dissing RedHat kernels saying as you did that they "conflict with my hardware". No offense meant but I'd be curious as to specifics of this. A "RedHat Kernel" is nothing more than a regular Linux kernel with some patches applied and almost every piece of hardware imaginable compiled as modules. When the kernel boots it detects a piece of hardware, loads the appropriate module, carries on. Many times people complain how "big" a RedHat kernel is. The entire .RPM might be big but not all of that loads into RAM when the machine boots. Only the modules for the hardware you have...

As to the original poster, if you installed RH 8.0 with 1 CPU and later add an additional CPU you'd want to upgrade to an SMP kernel. RedHat has released security/bugfix updated kernel versions 3 or 4 times since 8.0 came out. Latest is 2.4.18-19.8.0 and here are the various files:

kernel-2.4.18-19.8.0.i386.rpm
kernel-doc-2.4.18-19.8.0.i386.rpm
kernel-2.4.18-19.8.0.i686.rpm
kernel-smp-2.4.18-19.8.0.i686.rpm
kernel-bigmem-2.4.18-19.8.0.i686.rpm
kernel-source-2.4.18-19.8.0.i386.rpm
kernel-BOOT-2.4.18-19.8.0.i386.rpm
kernel-uml-2.4.18-19.8.0.i686.rpm
kernel-debug-2.4.18-19.8.0.i686.rpm

There are .i386 kernels which are NOT optimized for newer CPUs from PII forward and i686 kernels which are optimized for newer CPUs. Install the appropriate one for your hardware. There are -smp- kernels for SMP machines, -bigmem- kernels for machines with >4GB RAM, etc... If you selected GRUB as the boot loader then download one of these kernels, "rpm -ivh kernelfile.rpm --force" and then edit /etc/grub.conf to select it as default or select it manually at next boot. Simple and easy...

I gotta agree with wdingus, the real aspect to blame with RH is that when people try to compile their patched kernel code they tend to get bum compiles... and nothing is to blame aside from the .config file in /usr/src/linux.

However, I would never RPM a kernel. The RPMs are still made for world+dog, while I know what to exactly compile in and compile out. Its the same argument as the best cup of coffee I've ever had I made for myself.

Cheers,

Finegan

Here's one to try on for size... I administer about 20 Linux servers at customers sites mainly via dialup modem and SSH. How comfortable are you at compiling a new custom kernel and rebooting the machine remotely and potentially getting a very non-computer-literate person to fix it over the phone if it doesn't boot? Usually that's just picking a different kernel off a boot screen, but still... I feel pretty confident in putting a RedHat kernel on and rebooting and expecting the system to come up and not causing the customer any downtime.

On lots of different hardware so far I've had little to no problems with RedHat supplied .RPM kernels (fingers crossed). Hope it stays that way...

Well, in what you said here, you specifically say that RH has 2 kernels, one for a single CPU and a sperate one for SMP.
If you claim that RH is so much similar to the Vanilla kernel...why is there Only ONE vanilla kernel now, for both single cpu and smp??
It's the same vanilla kernel you use for smp...not like before when you had to download a specific smp kernel from kernel.org
but now, it's all integrated into a single kernel....unlike in Redhat..as you point out. So, indeed, there must be enough difference between RH's kernels and the vanilla kernel to have two separate kernels for a single and an smp computer to create problems with my hardware.

Thus...it is better..at least in my case...and perhaps in other's people cases as you also point out to compile vanilla kernels instead of dirstro's kernels. Which like finegan said, specially with RH, I wouldn't RPM the kernel.

cool.

zLinuxz

aahhhh, crap, I was typing the responce in my friends computer, and didn't notice that it was his account the one singed in!, oh well........what ever was written up there...it's mine..under Vieux.

hehe, sorry,

zLinuxz

Well, here's a section from a "make menuconfig" on a 2.4.18 kernel:

(4GB) High Memory Support [*] HIGHMEM I/O support (EXPERIMENTAL)
[ ] Math emulation[*] MTRR (Memory Type Range Register) support
[ ] Symmetric multi-processing support
[ ] Local APIC support on uniprocessors

It's not so much that RedHat has different kernels, rather kernels built with different configuration options. There's a specific configuration option as evidenced above to instruct the built kernel to support >1 CPUs or not. They build some with that option enabled, and some with that option disabled. I've not read up on it but there could be problems for some folks having SMP support enabled when they only have 1 CPU. Possibly...

Also, on the CPU type front, there are options in the stock kernel to select your CPU type and the build will be optimized for that type. RedHat just offers .i386 and .i686 optimized versions to cover the 2 most comon types of machines. A friend with a high-end Athlon has taken to re-compiling everything with Athlon-specific optimizations and says the speed increase is noticable. You can do this in a 'stock' kernel the same as you can a 'redhat' kernel. They're the same thing for the most part. The RedHat one just has a lot of options already selected.

( ) 386
( ) 486
( ) 586/K5/5x86/6x86/6x86MX
( ) Pentium-Classic
( ) Pentium-MMX
(X) Pentium-Pro/Celeron/Pentium-II
( ) Pentium-III/Celeron(Coppermine)
( ) Pentium-4
( ) K6/K6-II/K6-III
( ) Athlon/Duron/K7
( ) Elan
( ) Crusoe
( ) Winchip-C6
( ) Winchip-2
( ) Winchip-2A/Winchip-3
( ) CyrixIII/VIA-C3/VIA-C5

yeah, that's simple enough so that even I know that. The point, however, is that you can use the same kernel for 1 cpu or 2+ cpu's computers. And, since kernel 2.4.17+ the smp option is enabled by default. And even if you still use the configuratio nfor SMP...and you only have 1 cpu...it affects you in no bad way. You can use it like that no problem..as I understand, the kernel still detects whether or not you have 1 or 2 cpu's and if you kept the SMP mode...the kernel will automagically switch to a single cpu mode. I don't believe it will work the other way around...where if you omitted the SMP mode..it will switch to smp mode if you have more than 1 cpu...but from smp to single it does work.

Anyway, I find it more convenient and simply better to install a vanilla kernel than the RH kernels. Not that I have anything against RH...as you can see that's what I use, and I like RH very much.

cheers!