CentOS 7 reporting 1/6 of total ram installed on system
Posted: 2019/08/11 22:41:16
Hello,
I'd like to start by saying I am new to Nix operating systems and this is my first time posting on a forum of this nature. I'm trying to learn as much as I can and I would greatly appreciate anyone providing help or pointing me in the right direction. I hope that I am using this forum in the correct manner, apologies if I made a mistake.
I am configuring a lab environment with CentOS 7 as the host operating system (bare metal) on a Dell Poweredge R710 server. It is intended to by used as a hyper-visor for various Nix operating systems using vmware 15 pro. Previously I had windows server 2016 installed with system center but wanted to transition to nix as I am starting to like the operating systems much better. My issue is that after installation, my CentOS host is only showing 8GB of ram on the system even though there is currently 48GB installed. Commands like free and cat /proc/meminfo only show 8GB but running lshw clearly shows 48GB installed.
This is an entirely fresh install of Centos 7. The only additional software on the system is vmware 15 pro. There are no installed VMs.
Linux xx 3.10.0-957.27.2.el7.x86_64 #1 SMP Mon Jul 29 17:46:05 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux
```
free -m
total used free shared buff/cache available
Mem: 7797 2063 2276 24 3458 5250
Swap: 15361 0 15361
```
```
cat /proc/meminfo
MemTotal: 7984968 kB
MemFree: 2331096 kB
MemAvailable: 5376900 kB
Buffers: 1972 kB
Cached: 2994924 kB
...
SwapTotal: 15730684 kB
SwapFree: 15730684 kB
```
```
dmesg |egrep e820
[ 0.000000] e820: BIOS-provided physical RAM map:
[ 0.000000] BIOS-e820: [mem 0x0000000000010000-0x000000000009ffff] usable
[ 0.000000] BIOS-e820: [mem 0x0000000000100000-0x00000000ce777fff] usable
[ 0.000000] BIOS-e820: [mem 0x00000000ce778000-0x00000000ce977fff] reserved
[ 0.000000] BIOS-e820: [mem 0x00000000ce978000-0x00000000cea76fff] usable
[ 0.000000] BIOS-e820: [mem 0x00000000cea77000-0x00000000cea7bfff] ACPI NVS
[ 0.000000] BIOS-e820: [mem 0x00000000cea7c000-0x00000000ceafbfff] ACPI data
[ 0.000000] BIOS-e820: [mem 0x00000000ceafc000-0x00000000cef21fff] usable
[ 0.000000] BIOS-e820: [mem 0x00000000cef52000-0x00000000cef78fff] usable
[ 0.000000] BIOS-e820: [mem 0x00000000cf379000-0x00000000cf38efff] reserved
[ 0.000000] BIOS-e820: [mem 0x00000000cf38f000-0x00000000cf3cdfff] ACPI data
[ 0.000000] BIOS-e820: [mem 0x00000000cf3ce000-0x00000000cfffffff] reserved
[ 0.000000] BIOS-e820: [mem 0x00000000e0000000-0x00000000efffffff] reserved
[ 0.000000] BIOS-e820: [mem 0x00000000fe000000-0x00000000ffffffff] reserved
[ 0.000000] BIOS-e820: [mem 0x0000000100000000-0x000000022fffffff] usable
[ 0.000000] e820: update [mem 0xcc458018-0xcc45b057] usable ==> usable
[ 0.000000] e820: update [mem 0xcc42f018-0xcc457857] usable ==> usable
[ 0.000000] e820: update [mem 0xcc426018-0xcc42e057] usable ==> usable
[ 0.000000] e820: update [mem 0x00000000-0x00000fff] usable ==> reserved
[ 0.000000] e820: remove [mem 0x000a0000-0x000fffff] usable
[ 0.000000] e820: last_pfn = 0x230000 max_arch_pfn = 0x400000000
[ 0.000000] e820: update [mem 0xd0000000-0xffffffff] usable ==> reserved
[ 0.000000] e820: last_pfn = 0xcef79 max_arch_pfn = 0x400000000
[ 0.000000] e820: [mem 0xd0000000-0xdfffffff] available for PCI devices
[ 0.338001] e820: reserve RAM buffer [mem 0xcc426018-0xcfffffff]
[ 0.338003] e820: reserve RAM buffer [mem 0xcc42f018-0xcfffffff]
[ 0.338005] e820: reserve RAM buffer [mem 0xcc458018-0xcfffffff]
[ 0.338007] e820: reserve RAM buffer [mem 0xce778000-0xcfffffff]
[ 0.338009] e820: reserve RAM buffer [mem 0xcea77000-0xcfffffff]
[ 0.338011] e820: reserve RAM buffer [mem 0xcef22000-0xcfffffff]
[ 0.338013] e820: reserve RAM buffer [mem 0xcef79000-0xcfffffff]
```
```
lshw
-memory
description: System Memory
physical id: 1000
slot: System board or motherboard
size: 48GB
capabilities: ecc
configuration: errordetection=multi-bit-ecc
```
Following other forums that I could find on the issue, a lot of questions were asked about CentOS only showing about 95% of installed RAM due to kernel ram reservations. This clearly isn't my problem as my machine is only appearing to use 1/6 of installed RAM. The other question I commonly found was people asking a similar question about CentOS showing only half of available FREE RAM. Since my question is regarding RAM in general and not simply free RAM this was also not helpful for my situation. It is very likely that I am simply misunderstanding something so if that is the case I'd be very thankful to learn the reality of the issue I am facing. If anyone has any thoughts I'd be very appreciative to hear and consider them.
Thanks everyone,
Ash
I'd like to start by saying I am new to Nix operating systems and this is my first time posting on a forum of this nature. I'm trying to learn as much as I can and I would greatly appreciate anyone providing help or pointing me in the right direction. I hope that I am using this forum in the correct manner, apologies if I made a mistake.
I am configuring a lab environment with CentOS 7 as the host operating system (bare metal) on a Dell Poweredge R710 server. It is intended to by used as a hyper-visor for various Nix operating systems using vmware 15 pro. Previously I had windows server 2016 installed with system center but wanted to transition to nix as I am starting to like the operating systems much better. My issue is that after installation, my CentOS host is only showing 8GB of ram on the system even though there is currently 48GB installed. Commands like free and cat /proc/meminfo only show 8GB but running lshw clearly shows 48GB installed.
This is an entirely fresh install of Centos 7. The only additional software on the system is vmware 15 pro. There are no installed VMs.
Linux xx 3.10.0-957.27.2.el7.x86_64 #1 SMP Mon Jul 29 17:46:05 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux
```
free -m
total used free shared buff/cache available
Mem: 7797 2063 2276 24 3458 5250
Swap: 15361 0 15361
```
```
cat /proc/meminfo
MemTotal: 7984968 kB
MemFree: 2331096 kB
MemAvailable: 5376900 kB
Buffers: 1972 kB
Cached: 2994924 kB
...
SwapTotal: 15730684 kB
SwapFree: 15730684 kB
```
```
dmesg |egrep e820
[ 0.000000] e820: BIOS-provided physical RAM map:
[ 0.000000] BIOS-e820: [mem 0x0000000000010000-0x000000000009ffff] usable
[ 0.000000] BIOS-e820: [mem 0x0000000000100000-0x00000000ce777fff] usable
[ 0.000000] BIOS-e820: [mem 0x00000000ce778000-0x00000000ce977fff] reserved
[ 0.000000] BIOS-e820: [mem 0x00000000ce978000-0x00000000cea76fff] usable
[ 0.000000] BIOS-e820: [mem 0x00000000cea77000-0x00000000cea7bfff] ACPI NVS
[ 0.000000] BIOS-e820: [mem 0x00000000cea7c000-0x00000000ceafbfff] ACPI data
[ 0.000000] BIOS-e820: [mem 0x00000000ceafc000-0x00000000cef21fff] usable
[ 0.000000] BIOS-e820: [mem 0x00000000cef52000-0x00000000cef78fff] usable
[ 0.000000] BIOS-e820: [mem 0x00000000cf379000-0x00000000cf38efff] reserved
[ 0.000000] BIOS-e820: [mem 0x00000000cf38f000-0x00000000cf3cdfff] ACPI data
[ 0.000000] BIOS-e820: [mem 0x00000000cf3ce000-0x00000000cfffffff] reserved
[ 0.000000] BIOS-e820: [mem 0x00000000e0000000-0x00000000efffffff] reserved
[ 0.000000] BIOS-e820: [mem 0x00000000fe000000-0x00000000ffffffff] reserved
[ 0.000000] BIOS-e820: [mem 0x0000000100000000-0x000000022fffffff] usable
[ 0.000000] e820: update [mem 0xcc458018-0xcc45b057] usable ==> usable
[ 0.000000] e820: update [mem 0xcc42f018-0xcc457857] usable ==> usable
[ 0.000000] e820: update [mem 0xcc426018-0xcc42e057] usable ==> usable
[ 0.000000] e820: update [mem 0x00000000-0x00000fff] usable ==> reserved
[ 0.000000] e820: remove [mem 0x000a0000-0x000fffff] usable
[ 0.000000] e820: last_pfn = 0x230000 max_arch_pfn = 0x400000000
[ 0.000000] e820: update [mem 0xd0000000-0xffffffff] usable ==> reserved
[ 0.000000] e820: last_pfn = 0xcef79 max_arch_pfn = 0x400000000
[ 0.000000] e820: [mem 0xd0000000-0xdfffffff] available for PCI devices
[ 0.338001] e820: reserve RAM buffer [mem 0xcc426018-0xcfffffff]
[ 0.338003] e820: reserve RAM buffer [mem 0xcc42f018-0xcfffffff]
[ 0.338005] e820: reserve RAM buffer [mem 0xcc458018-0xcfffffff]
[ 0.338007] e820: reserve RAM buffer [mem 0xce778000-0xcfffffff]
[ 0.338009] e820: reserve RAM buffer [mem 0xcea77000-0xcfffffff]
[ 0.338011] e820: reserve RAM buffer [mem 0xcef22000-0xcfffffff]
[ 0.338013] e820: reserve RAM buffer [mem 0xcef79000-0xcfffffff]
```
```
lshw
-memory
description: System Memory
physical id: 1000
slot: System board or motherboard
size: 48GB
capabilities: ecc
configuration: errordetection=multi-bit-ecc
```
Following other forums that I could find on the issue, a lot of questions were asked about CentOS only showing about 95% of installed RAM due to kernel ram reservations. This clearly isn't my problem as my machine is only appearing to use 1/6 of installed RAM. The other question I commonly found was people asking a similar question about CentOS showing only half of available FREE RAM. Since my question is regarding RAM in general and not simply free RAM this was also not helpful for my situation. It is very likely that I am simply misunderstanding something so if that is the case I'd be very thankful to learn the reality of the issue I am facing. If anyone has any thoughts I'd be very appreciative to hear and consider them.
Thanks everyone,
Ash