RHEL5 on a compaq ml570 with Xen kernel?

[dwerthmu]

I've got a Dual core system 3ghz with Scalix 1.3 enterprise running. The system has 8 Gigs or ram. But the the default kernel doesn't recognize more than 4 gigs. But if I run the Xen kernel I get to see all 8 gigs.

Any disadvantage with running scalix with the xen kernel? not in a virtual system.


Any performance tips for a ml570 system with 8 SIS 2.5" 10k rpm, drives on a P800 controller?


How about a file system layout that performs best?
(All RAID 1+0)
/var 200G
/boot 100m
/usr 10G
/ 10G

[Valerion]

The Xen kernel probably has support for more accessible RAM. You can set this in the kernel and recompile to get the same results. Your distribution may also have pre-built kernels with this option enabled. I know CentOS/RHEL 4 does have them. Seems to be removed in CentOS 5. Not sure how to enable it in that case.

[EDIT] Oh wait ...

Available Packages
Name : kernel-PAE
Arch : i686
Version: 2.6.18
Release: 53.1.13.el5
Size : 13 M
Repo : updates
Summary: The Linux kernel compiled for PAE capable machines.
Description:
This package includes a version of the Linux kernel with support for up to
64GB of high memory. It requires a CPU with Physical Address Extensions (PAE).
The non-PAE kernel can only address up to 4GB of memory.
Install the kernel-PAE package if your machine has more than 4GB of memory.


So you will need the PAE kernel on CentOS (and probably RHEL). If you are on a different platform there should be a version for you.

[dwerthmu]

Yes that does the trick. I thought the installer would have picked the correct kernel.

sudo yum install kernel-PAE.i686

set the selection order in /etc/grub.conf

reboot and all is good!