Centos 7 Not using memory > 1TB RAM


New Member
Jun 9, 2022
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I have a System Centos 7 has been running with 768GB of Ram for a couple of years now . added 512 GB ram to bring itthe 1.25 TB of ram.
Installed it no problem , the Mother sees it , lshw sees it , However the OS is only reporting using 1TB of ram

I'm sure it is something simple I'm missing. But I can't figure it out

[root@xtc kernel]# lshw
    description: Desktop Computer
    product: RS700-E9-RS4 (SKU)
    version: Rev 1.xx
    serial: H7S0CG0001FX
    width: 64 bits
    capabilities: smbios-3.0.0 dmi-3.0.0 smp vsyscall32
    configuration: boot=normal chassis=desktop family=Server sku=SKU uuid=AB1233                                                                         EC-69AC-7411-A698-88D7F6AECDE8
       description: Motherboard
       product: Z11PP-D24 Series
       vendor: ASUSTeK COMPUTER INC.
       physical id: 0
       version: Rev 1.xx
       serial: 176803057400060
       slot: To Be Filled By O.E.M.
          description: BIOS
          vendor: American Megatrends Inc.
          physical id: 0
          version: 0403
          date: 07/04/2017
          size: 64KiB
          capacity: 16MiB
          capabilities: pci apm upgrade shadowing cdboot bootselect socketedrom                                                                          edd int13floppy1200 int13floppy720 int13floppy2880 int5printscreen int9keyboard                                                                          int14serial int17printer acpi usb biosbootspecification uefi
          description: System Memory
          physical id: 31
          slot: System board or motherboard
          size: 1280GiB
          capabilities: ecc
          configuration: errordetection=ecc

[root@xtc kernel]# free -h
              total        used        free      shared  buff/cache   available
Mem:           1.0T         11G        993G         19M        351M        992G
Swap:          935G          0B        935G
[root@xtc kernel]# uname -a
Linux xtc 3.10.0-1160.66.1.el7.x86_64 #1 SMP Wed May 18 16:02:34 UTC 2022 x86_64 x86_64 x86_64 GNU/Linux
[root@xtc kernel]# cat /etc/redhat-release
CentOS Linux release 7.9.2009 (Core)
[root@xtc kernel]#
[root@xtc kernel]# cat /proc/meminfo
MemTotal:       1054167808 kB
MemFree:        608321080 kB
MemAvailable:   1035182472 kB
Buffers:            1400 kB
Cached:         427501204 kB
SwapCached:            0 kB
Active:         23638748 kB
Inactive:       409055088 kB
Active(anon):    5196164 kB
Inactive(anon):    19300 kB
Active(file):   18442584 kB
Inactive(file): 409035788 kB
Unevictable:           0 kB
Mlocked:               0 kB
SwapTotal:      980955128 kB
SwapFree:       980955128 kB
Dirty:             16520 kB
Writeback:        316780 kB
AnonPages:       5191820 kB
Mapped:           675296 kB
Shmem:             23720 kB
Slab:            1681048 kB
SReclaimable:    1325592 kB
SUnreclaim:       355456 kB
KernelStack:       29504 kB
PageTables:        77344 kB
NFS_Unstable:     284904 kB
Bounce:                0 kB
WritebackTmp:          0 kB
CommitLimit:    1508039032 kB
Committed_AS:   12482536 kB
VmallocTotal:   34359738367 kB
VmallocUsed:     2269720 kB
VmallocChunk:   33951551484 kB
Percpu:           100928 kB
HardwareCorrupted:     0 kB
AnonHugePages:   1560576 kB
CmaTotal:              0 kB
CmaFree:               0 kB
HugePages_Total:       0
HugePages_Free:        0
HugePages_Rsvd:        0
HugePages_Surp:        0
Hugepagesize:       2048 kB
DirectMap4k:      320044 kB
DirectMap2M:     8738816 kB
DirectMap1G:    1064304640 kB

I have the same problem.
Have you resolved it?
Welcome to the forums
the original poster has not been seen in over a year, you would do better starting a new thread of your own.
With ram, the MB and CPU may see what you have installed, but if it exceeds the design parameters of the MB or CPU, only the design maximum will get used. [when needed]
I found the solution.
See attachment.


  • 2023-09-22 09.24.40.jpg
    2023-09-22 09.24.40.jpg
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