Physical Memory not detected (?) not used

SUSE Linux Enterprise Server SLES SAP Applications
1


Hello
The Physical memory reported is not detected in the system. Only 21GB are shown, instead of the 32 available. I checked the article https://www.suse.com/support/kb/doc/?id=000018341 but it didn’t help with this issue. Any ideas? Thanks!

2

@Agamemnon Hi, time to break out the calculator… :wink:
Run the following command;

journalctl -b | grep e820

Then need to calculate/convert all the usable entries to see how much RAM is available…

3

Hello Malcom,
That’s the output:
May 05 14:17:44 localhost kernel: BIOS-e820: [mem 0x0000000000000000-0x000000000009fbff] usable
May 05 14:17:44 localhost kernel: BIOS-e820: [mem 0x000000000009fc00-0x000000000009ffff] reserved
May 05 14:17:44 localhost kernel: BIOS-e820: [mem 0x00000000000dc000-0x00000000000fffff] reserved
May 05 14:17:44 localhost kernel: BIOS-e820: [mem 0x0000000000100000-0x00000000affebfff] usable
May 05 14:17:44 localhost kernel: BIOS-e820: [mem 0x00000000affec000-0x00000000affedfff] reserved
May 05 14:17:44 localhost kernel: BIOS-e820: [mem 0x00000000affee000-0x00000000afffafff] ACPI data
May 05 14:17:44 localhost kernel: BIOS-e820: [mem 0x00000000afffb000-0x00000000afffffff] ACPI NVS
May 05 14:17:44 localhost kernel: BIOS-e820: [mem 0x00000000fec00000-0x00000000fec00fff] reserved
May 05 14:17:44 localhost kernel: BIOS-e820: [mem 0x00000000fed00000-0x00000000fed00fff] reserved
May 05 14:17:44 localhost kernel: BIOS-e820: [mem 0x00000000fed04000-0x00000000fed04fff] reserved
May 05 14:17:44 localhost kernel: BIOS-e820: [mem 0x00000000fee00000-0x00000000fee00fff] reserved
May 05 14:17:44 localhost kernel: BIOS-e820: [mem 0x00000000ffc00000-0x00000000ffffffff] reserved
May 05 14:17:44 localhost kernel: BIOS-e820: [mem 0x0000000100000000-0x000000084fffffff] usable
May 05 14:17:44 localhost kernel: e820: update [mem 0x00000000-0x00000fff] usable ==> reserved
May 05 14:17:44 localhost kernel: e820: remove [mem 0x000a0000-0x000fffff] usable
May 05 14:17:44 localhost kernel: e820: reserve RAM buffer [mem 0x0009fc00-0x0009ffff]
May 05 14:17:44 localhost kernel: e820: reserve RAM buffer [mem 0xaffec000-0xafffffff]
Any idea how to convert / calculate the entries? The resources are limited. 32GB of memory in the host machine, but it looks like that above 28GB, the system uses around 20 of them.

4

@Agamemnon Hi, calculation as follows;

BIOS-e820: [mem 0x0000000000000000-0x000000000009fbff] usable
echo $((0x9fbff))
654335

BIOS-e820: [mem 0x0000000000100000-0x00000000affebfff] usable
echo $((0x100000))
1048576

echo $((0xaffebfff))
2952708095

BIOS-e820: [mem 0x0000000100000000-0x000000084fffffff] usable
echo $((0x100000000))
4294967296

echo $((0x84fffffff))
35701915647

e820: update [mem 0x00000000-0x00000fff] usable ==> reserved (subtract)
echo $((0xfff))
4095

e820: remove [mem 0x000a0000-0x000fffff] usable (subtract)
echo $((0xa0000))
655360

echo $((0xfffff))
1048575

Divide result by 1024/1024

eg 654335/1024/1024

654335		654335	0.624022483825684
			
2952708095	1048576	2951659519	2814.92187404633
			
			
35701915647	4294967296	31406948351	29951.9999990463

SUM			32767.5458955765

4095		4095	0.003905296325684
			
1048575	655360	393215	0.374999046325684
			
SUBRACT			32767.1669912338

RESULT			31.9991865148768

31.999GB

So it looks like an application issue, not system issue…

5

Indeed! In the meantime I changed a setting in the parallels and got the memory needed. Now the challenge is to increase the partition space…