Use all of my RAM in Ubuntu Server

**dolphin194** · May 8th, 2012

I was wondering if I can use all 8 gigs of my RAM in my server computer.

Every forum post I have seen online is that this is impossible to do, and that only applied to Windows. However, people in real life have said that Linux 32-Bit is capable of using all of the RAM a computer. I have no idea who is correct.

My computer is a Dell PowerEdge 2650 running Ubuntu Server 10.04. It has 32-Bit Processors (as in Intel Xeon 2.8GHz). It has 8GB of RAM installed in it.

A website at http://www.memorystock.com/memory/De...rEdge2650.html says this:
You can upgrade your Dell PowerEdge 2650 Server to up to a maximum of 12.0 GB

The document at this place says:
It provides SDRAM memory capabilities from 256MB up to 12GB

This is proof that the computer is capable of using all of the RAM.

How can I use all 8GB of my RAM in this computer?

**Cheesemill** · May 8th, 2012

You can use all of the memory if you have a PAE enabled kernel installed, which I believe comes as default on 10.04 server.

What is the output of:

Code:

uname -a

and

Code:

free -m

**dolphin194** · May 8th, 2012

The output of uname -a is:

Code:

Linux PowerEdge 2.6.32-40-generic-pae #87-Ubuntu SMP Mon Mar 5 21:44:34 UTC 2012 i686 GNU/Linux

The output of free -m is:

Code:

             total       used       free     shared    buffers     cached
Mem:          3782        239       3542          0         38        106
-/+ buffers/cache:         94       3687
Swap:         5711          0       5711

However, there is 8GB of RAM installed in the machine.

**Cheesemill** · May 8th, 2012

OK, you have the correct kernel installed so your machine should be reporting the full amount. What is the output of:

Code:

cat /proc/cpuinfo

**dolphin194** · May 8th, 2012

The output of /proc/cpuinfo is:

Code:

processor    : 0
vendor_id    : GenuineIntel
cpu family    : 15
model        : 2
model name    : Intel(R) Xeon(TM) CPU 2.80GHz
stepping    : 9
cpu MHz        : 2790.931
cache size    : 512 KB
physical id    : 0
siblings    : 2
core id        : 0
cpu cores    : 1
apicid        : 0
initial apicid    : 0
fdiv_bug    : no
hlt_bug        : no
f00f_bug    : no
coma_bug    : no
fpu        : yes
fpu_exception    : yes
cpuid level    : 2
wp        : yes
flags        : fpu vme de pse tsc msr pae mce cx8 apic mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe pebs bts cid xtpr
bogomips    : 5581.86
clflush size    : 64
cache_alignment    : 128
address sizes    : 36 bits physical, 32 bits virtual
power management:

processor    : 1
vendor_id    : GenuineIntel
cpu family    : 15
model        : 2
model name    : Intel(R) Xeon(TM) CPU 2.80GHz
stepping    : 9
cpu MHz        : 2790.931
cache size    : 512 KB
physical id    : 3
siblings    : 2
core id        : 0
cpu cores    : 1
apicid        : 6
initial apicid    : 6
fdiv_bug    : no
hlt_bug        : no
f00f_bug    : no
coma_bug    : no
fpu        : yes
fpu_exception    : yes
cpuid level    : 2
wp        : yes
flags        : fpu vme de pse tsc msr pae mce cx8 apic mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe pebs bts cid xtpr
bogomips    : 5581.77
clflush size    : 64
cache_alignment    : 128
address sizes    : 36 bits physical, 32 bits virtual
power management:

processor    : 2
vendor_id    : GenuineIntel
cpu family    : 15
model        : 2
model name    : Intel(R) Xeon(TM) CPU 2.80GHz
stepping    : 9
cpu MHz        : 2790.931
cache size    : 512 KB
physical id    : 0
siblings    : 2
core id        : 0
cpu cores    : 1
apicid        : 1
initial apicid    : 1
fdiv_bug    : no
hlt_bug        : no
f00f_bug    : no
coma_bug    : no
fpu        : yes
fpu_exception    : yes
cpuid level    : 2
wp        : yes
flags        : fpu vme de pse tsc msr pae mce cx8 apic mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe pebs bts cid xtpr
bogomips    : 5581.74
clflush size    : 64
cache_alignment    : 128
address sizes    : 36 bits physical, 32 bits virtual
power management:

processor    : 3
vendor_id    : GenuineIntel
cpu family    : 15
model        : 2
model name    : Intel(R) Xeon(TM) CPU 2.80GHz
stepping    : 9
cpu MHz        : 2790.931
cache size    : 512 KB
physical id    : 3
siblings    : 2
core id        : 0
cpu cores    : 1
apicid        : 7
initial apicid    : 7
fdiv_bug    : no
hlt_bug        : no
f00f_bug    : no
coma_bug    : no
fpu        : yes
fpu_exception    : yes
cpuid level    : 2
wp        : yes
flags        : fpu vme de pse tsc msr pae mce cx8 apic mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe pebs bts cid xtpr
bogomips    : 5581.84
clflush size    : 64
cache_alignment    : 128
address sizes    : 36 bits physical, 32 bits virtual
power management:

so it does support pae

**Cheesemill** · May 8th, 2012

How much memory does the BIOS report at boot?

You probably have to either change a BIOS setting or update your BIOS for it to recognise all of the RAM.

**dolphin194** · May 8th, 2012

Unfortunately I do not have physical access to the machine, only SSH and etc. right now, but I will later in the day. I will check the BIOS to see if there are any issues in there.

**Cheesemill** · May 8th, 2012

I've just looked at the official Dell documentation and it gives a maximum of 6GB of RAM for the machine, the motherboard is probably only capable of recognising 1GB of memory per slot.

If you are using 4x2GB sticks then the BIOS would only recognise 4x1GB

Look at the second link on this page:
http://support.dell.com/support/edoc...0/en/index.htm