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*SOLVED* SMP kernel vs PAE [message #15141]

Thu, 19 July 2007 22:29

jpastore
Messages: 21
Registered: July 2007
Location: South Florida

Junior Member

I have a Dell PowerEdge 1900 with 6G of Ram and a quadcore processor. After reviewing the different kernel flavors ( http://wiki.openvz.org/Different_kernel_flavors_%28UP%2C_SMP %2C_ENTERPRISE%2C_ENTNOSPLIT%29)

I chose the PAE kernel, which hangs on boot. So I decided to fall back to the SMP kernel.

top shows 6G of Ram available.

should I bother trying to get the PAE kernel working?

-Jon

[Updated on: Fri, 20 July 2007 14:43] by Moderator

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Re: SMP kernel vs PAE [message #15145 is a reply to message #15141]

Fri, 20 July 2007 07:02

dev
Messages: 1693
Registered: September 2005
Location: Moscow

Senior Member

1. what kernel version have you used? the answers/questions depend on this Smile

2. i686 or x86-64? I assume 1st.
3. it is binary kernel from openvz.org or compiled by yourself?

http://static.openvz.org/userbars/openvz-developer.png

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Re: SMP kernel vs PAE [message #15176 is a reply to message #15145]

Fri, 20 July 2007 14:09

jpastore
Messages: 21
Registered: July 2007
Location: South Florida

Junior Member

uname -a
Linux HOSTNAME-OMITTED 2.6.18-ovz028stab035.1-smp #1 SMP Sat Jun 9 12:09:51 MSD 2007 x86_64 x86_64 x86_64 GNU/Linux

rpm -qa |grep ovz
ovzkernel-2.6.18-8.1.4.el5.028stab035.1
ovzkernel-PAE-2.6.18-8.1.4.el5.028stab035.1
kernel-smp-2.6.18-ovz028stab035.1

I followed the instructions from the wiki and after finishing the instructions I found another set of work around instructions for dealing with x86_64. I did not compile them myself I used yum to fetch them from the openvz repository.

Thanks

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Re: SMP kernel vs PAE [message #15178 is a reply to message #15176]

Fri, 20 July 2007 14:19

dev
Messages: 1693
Registered: September 2005
Location: Moscow

Senior Member

PAE kernel is for i686 only. it has even i686 in rpm name Smile

For x86-64 there is only one RHEL5 kernel flavour and it's SMP by default.

So your currently loaded kernel (2.6.18-ovz028stab035.1-smp as shown by uname output) is the right choice for you.

[Updated on: Fri, 20 July 2007 14:20]

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Re: SMP kernel vs PAE [message #15180 is a reply to message #15178]

Fri, 20 July 2007 14:27

jpastore
Messages: 21
Registered: July 2007
Location: South Florida

Junior Member

Thank you I didn't realize it was i686 only. I only tried to get it work when I realized I had 6G of ram and the chart stated that over 4G you should PAE.

Am I going to fully utilize the 6G of ram with the SMP kernel? I see that it recognizes it, but the wiki states otherwise.

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Re: SMP kernel vs PAE [message #15181 is a reply to message #15180]

Fri, 20 July 2007 14:31

dev
Messages: 1693
Registered: September 2005
Location: Moscow

Senior Member

there is no 4GB limit on x86-64, so the whole RAM will be used.

there is a note in wiki

Note: When using a 64-bit processor and operating system, you need only select the SMP or non-SMP version. 64-bit linux can access the entire 64Gb of ram in ZONE_NORMAL (low memory). PAE and 4GB/4GB splitting are only needed for 32-bit OS, and so are not necessary and are disabled by default in 64-bit kernels.

And I've also added the table in question is i686-specific.
Sorry for the confusion :/

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