Hi Everyone,
My server is only seeing 4.8 GB out of 6 GB available. I don't know
why.
I have a CentOS 4.4 x86_64 server running on a Tyan s2895 with 6 GB of
RAM (two 1 GB sticks and 2 2 GB sticks). I upgraded the RAM, powered up
the server, and when CentOS was finished booting, checked the available
RAM with free. This is what it's reporting:
total used free shared
buffers cached
Mem: 4809064 4769492 39572 0 197156
3127704
-/+ buffers/cache: 1444632 3364432
Swap: 2064376 176 2064200
The BIOS sees all of the RAM. In fact, it looks to me like the kernel
knows 6 GB is available. But, it is only using 4.8 GB because I see
this in dmesg:
Memory: 4808464k/6291456k available (2106k kernel code, 0k reserved,
1299k data, 196k init)
What happened to the other 1 GB+ of RAM?
BTW, the server isn't running all the newest updates, but it is running
the latest CentOS 4 kernel (2.6.9-42.0.10.ELsmp).
Regards,
Ranbir
--
Kanwar Ranbir Sandhu
Linux 2.6.19-1.2911.fc6 i686 GNU/Linux
11:39:08 up 2 days, 10:28, 2 users, load average: 1.18, 0.64, 0.60
Fedora has a PAE kernel which is useful in instances like this, what
would be the CentOS alternative to that?
-Drew
-----Original Message-----
From: centos-bounces at centos.org [mailto:centos-bounces at centos.org] On
Behalf Of Kanwar Ranbir Sandhu
Sent: Monday, March 05, 2007 11:47 AM
To: CentOS mailing list
Subject: [CentOS] CentOS 4.4 not seeing all RAM
Hi Everyone,
My server is only seeing 4.8 GB out of 6 GB available. I don't know
why.
I have a CentOS 4.4 x86_64 server running on a Tyan s2895 with 6 GB of
RAM (two 1 GB sticks and 2 2 GB sticks). I upgraded the RAM, powered up
the server, and when CentOS was finished booting, checked the available
RAM with free. This is what it's reporting:
total used free shared
buffers cached
Mem: 4809064 4769492 39572 0 197156
3127704
-/+ buffers/cache: 1444632 3364432
Swap: 2064376 176 2064200
The BIOS sees all of the RAM. In fact, it looks to me like the kernel
knows 6 GB is available. But, it is only using 4.8 GB because I see
this in dmesg:
Memory: 4808464k/6291456k available (2106k kernel code, 0k reserved,
1299k data, 196k init)
What happened to the other 1 GB+ of RAM?
BTW, the server isn't running all the newest updates, but it is running
the latest CentOS 4 kernel (2.6.9-42.0.10.ELsmp).
Regards,
Ranbir
--
Kanwar Ranbir Sandhu
Linux 2.6.19-1.2911.fc6 i686 GNU/Linux
11:39:08 up 2 days, 10:28, 2 users, load average: 1.18, 0.64, 0.60
_______________________________________________
CentOS mailing list
CentOS at centos.org
http://lists.centos.org/mailman/listinfo/centos
Kanwar Ranbir Sandhu wrote:> Hi Everyone, > > My server is only seeing 4.8 GB out of 6 GB available. I don't know > why. > > I have a CentOS 4.4 x86_64 server running on a Tyan s2895 with 6 GB of > RAM (two 1 GB sticks and 2 2 GB sticks). I upgraded the RAM, powered up > the server, and when CentOS was finished booting, checked the available > RAM with free. This is what it's reporting: > > total used free shared > buffers cached > Mem: 4809064 4769492 39572 0 197156 > 3127704 > -/+ buffers/cache: 1444632 3364432 > Swap: 2064376 176 2064200 > > The BIOS sees all of the RAM. In fact, it looks to me like the kernel > knows 6 GB is available. But, it is only using 4.8 GB because I see > this in dmesg: > > Memory: 4808464k/6291456k available (2106k kernel code, 0k reserved, > 1299k data, 196k init) > > What happened to the other 1 GB+ of RAM?It's probably a memory hole mapping setting ... you probably need to enable it - have a look under 'Advanced Hammer Configuration' (or similar) in the BIOS James Pearson
Interesting. I wonder if it has something to do with the chipset the
motherboard is using?
Here's free on a new server of mine, with 16gb, runing x86_64, centos 4.4
[root at vmhost ~]# free -m
total used free shared buffers cached
Mem: 16029 16004 24 0 2144 13002
-/+ buffers/cache: 858 15171
Swap: 1983 0 1983
[root at vmhost ~]# dmesg |grep Memory
Memory: 16413932k/17563648k available (2106k kernel code, 0k reserved,
1299k data, 196k init)
I see the same thing you do, basiclly a gigabyte is "missing"
However, on a machine with only 2g of ram, less ram is 'missing':
[root at incognito ~]# dmesg |grep Memory
Memory: 2054916k/2096896k available (2106k kernel code, 0k reserved,
1299k data, 196k init)
[root at incognito ~]# free -m
total used free shared buffers cached
Mem: 2007 1988 18 0 31 1827
-/+ buffers/cache: 129 1877
Swap: 996 0 995
Both these boxes are brand new Dells, first one's a 2950, the other an 860.
Gordon
On 3/5/07, Kanwar Ranbir Sandhu <m3freak at thesandhufamily.ca>
wrote:> Hi Everyone,
>
> My server is only seeing 4.8 GB out of 6 GB available. I don't know
> why.
>
> I have a CentOS 4.4 x86_64 server running on a Tyan s2895 with 6 GB of
> RAM (two 1 GB sticks and 2 2 GB sticks). I upgraded the RAM, powered up
> the server, and when CentOS was finished booting, checked the available
> RAM with free. This is what it's reporting:
>
> total used free shared
> buffers cached
> Mem: 4809064 4769492 39572 0 197156
> 3127704
> -/+ buffers/cache: 1444632 3364432
> Swap: 2064376 176 2064200
>
> The BIOS sees all of the RAM. In fact, it looks to me like the kernel
> knows 6 GB is available. But, it is only using 4.8 GB because I see
> this in dmesg:
>
> Memory: 4808464k/6291456k available (2106k kernel code, 0k reserved,
> 1299k data, 196k init)
>
> What happened to the other 1 GB+ of RAM?
>
> BTW, the server isn't running all the newest updates, but it is running
> the latest CentOS 4 kernel (2.6.9-42.0.10.ELsmp).
>
> Regards,
>
> Ranbir
> --
> Kanwar Ranbir Sandhu
> Linux 2.6.19-1.2911.fc6 i686 GNU/Linux
> 11:39:08 up 2 days, 10:28, 2 users, load average: 1.18, 0.64, 0.60
>
>
> _______________________________________________
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>