Summary: RHEL 5.1 (32 bit) shows 3GB RAM though there's 16GB physical

[sunhux G]

Hi

top & dmesg now shows the full 16Gb memory after
we booted up from the PAE kernel, thanks

top:
Mem:  16634124k total, 16180672k used,   453452k free,   139676k buffers
Swap:  8193108k total,  1222860k used,  6970248k free, 14811976k cached


# dmesg | grep -i mem
16256MB HIGHMEM available.
896MB LOWMEM available.
Memory for crash kernel (0x0 to 0x0) notwithin permissible range
  HighMem zone: 4161536 pages, LIFO batch:31
Memory: 16630616k/17563648k available (2077k kernel code, 144604k reserved,
860k data, 220k init, 15858988k highmem)


=======================================
# dmidecode | grep -e Memory\ Device$ -A5 | more
Memory Device
        Array Handle: 0x0171
        Error Information Handle: Not Provided
        Total Width: 72 bits
        Data Width: 64 bits
        Size: 2048 MB
--
Memory Device
        Array Handle: 0x0171
        Error Information Handle: Not Provided
        Total Width: 72 bits
        Data Width: 64 bits
        Size: 2048 MB
--
Memory Device
        Array Handle: 0x0171
        Error Information Handle: Not Provided
        Total Width: 72 bits
        Data Width: 64 bits
        Size: 1024 MB
--
Memory Device
        Array Handle: 0x0171
        Error Information Handle: Not Provided
        Total Width: 72 bits
        Data Width: 64 bits
        Size: 1024 MB
--
Memory Device
        Array Handle: 0x0171
        Error Information Handle: Not Provided
        Total Width: 72 bits
        Data Width: 64 bits
        Size: No Module Installed
--
Memory Device
        Array Handle: 0x0171
        Error Information Handle: Not Provided
        Total Width: 72 bits
        Data Width: 64 bits
        Size: No Module Installed
--
Memory Device
        Array Handle: 0x0171
        Error Information Handle: Not Provided
        Total Width: 72 bits

        Data Width: 64 bits
        Size: No Module Installed
--
Memory Device
        Array Handle: 0x0171
        Error Information Handle: Not Provided
        Total Width: 72 bits
        Data Width: 64 bits
        Size: No Module Installed
--
Memory Device
        Array Handle: 0x0171
        Error Information Handle: Not Provided
        Total Width: 72 bits
        Data Width: 64 bits
        Size: 2048 MB
--
Memory Device
        Array Handle: 0x0171
        Error Information Handle: Not Provided
        Total Width: 72 bits
        Data Width: 64 bits
        Size: 2048 MB



On Fri, Dec 25, 2009 at 6:18 PM, sunhux G <sunhux at gmail.com> wrote:

>
> > Is your physical memory correctly showing up now?
>
> Thanks very much chaps, I'll only know in the next approved
> downtime which is about 3-4 weeks away.  Just curious, if
> it's non-PAE, shouldn't it show as 4GB instead of 3GB?
>
> Anyway, I'll update this least after the downtime
>
>
> Thanks
> U
>


Hi,
Yes ! there is no harm in commenting out the kernel without PAE.
The change in the kernel will absolutely not have any impact on your oracle
environment.
I had done this many times on my oracle environment and nothing has gone
wrong.
Is your physical memory correctly showing up now?
Cheers,
Ram

========================================

Hi Chaps,


rpm -qa | grep -i pae       gave
kernel-PAE-2.6.18-53.el5

&    ls -d  /boot/vm*      gave
vmlinuz-2.6.18-53.el5
vmlinuz-2.6.18-53.el5PAE

& /etc/grub.conf has both the above.


So can I say the best thing to do now is :
comment out in grub.conf the non-Pae entry so that by default
it boots up from the PAE kernel & nobody would accidentally
boots up from the non-PAE

Also, is there any impact to Oracle & web applications
if I boot up from the PAE kernel?  Any precautions?


Thanks