thaiwiz Xen
2005-Sep-16 09:29 UTC
[Xen-users] Seeing only 832 MB of 4 GB RAM on FC4 (2.6.12-1.1447_FC4xen0)
My machine is dual Xeon with 4GB RAM.
When I boot with 2.6.12-1.1447_FC4smp, all 4GB RAM is seen and used
normally.
However, when I boot with 2.6.12-1.1447_FC4xen0, only 832MB RAM can be
used. The warning message indicates that I should use a HIGHMEM enabled
kernel.
1. How can I define HIGHMEM?
2. Can it be done with this binary FC4 release or I have to compile my
own kernel and set HIGHMEM?
3. Anyone has RPM built for this?
Thanks lists,
Attached is the message:
#dmesg
Linux version 2.6.12-1.1447_FC4xen0
(bhcompile@decompose.build.redhat.com) (gcc
version 4.0.1 20050727 (Red Hat 4.0.1-5)) #1 SMP Fri Aug 26 21:13:28 EDT
2005
BIOS-provided physical RAM map:
Xen: 0000000000100000 - 00000000cdb30000 (usable)
Warning only 832MB will be used.
Use a HIGHMEM enabled kernel.
832MB LOWMEM available.
Using x86 segment limits to approximate NX protection
On node 0 totalpages: 212992
DMA zone: 212992 pages, LIFO batch:31
Normal zone: 0 pages, LIFO batch:1
HighMem zone: 0 pages, LIFO batch:1
found SMP MP-table at 000f67d0
DMI present.
Intel MultiProcessor Specification v1.4
Virtual Wire compatibility mode.
OEM ID: INTEL Product ID: Lindenhurst APIC at: 0xFEE00000
I/O APIC #2 Version 32 at 0xFEC00000.
I/O APIC #3 Version 32 at 0xFEC10000.
Enabling APIC mode: Flat. Using 2 I/O APICs
Processors: 2
IRQ lockup detection disabled
Allocating PCI resources starting at cdc00000 (gap: cdb30000:324d0000)
...
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Ernst Bachmann
2005-Sep-16 09:40 UTC
Re: [Xen-users] Seeing only 832 MB of 4 GB RAM on FC4 (2.6.12-1.1447_FC4xen0)
On Friday 16 September 2005 11:29, thaiwiz Xen wrote:> My machine is dual Xeon with 4GB RAM. > When I boot with 2.6.12-1.1447_FC4smp, all 4GB RAM is seen and used > normally. > However, when I boot with 2.6.12-1.1447_FC4xen0, only 832MB RAM can be > used. The warning message indicates that I should use a HIGHMEM enabled > kernel. > 1. How can I define HIGHMEM? > 2. Can it be done with this binary FC4 release or I have to compile my > own kernel and set HIGHMEM? > 3. Anyone has RPM built for this?Even with Highmem enabled, you''ll probably only have about 3GB of your ram usable. To get all of your ram, you''ll have to use a PAE enabled kernel. PAE uses paging to make the rest of your ram available, just like EMS did in the old DOS days... The only way to get all 4GB available as "real ram" is to use a 64bit kernel (if your xeons have em64t). PAE and 64bit support aren''t available in xen-2.*, though, so you''ll either have to live with 3GB ram or try xen-3. /Ernst _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users