topic Difference in RAM values, like Real vs. Virtual in General Topics

Difference in RAM values, like Real vs. Virtual

Christian_Koehl — Wed, 14 Apr 2021 12:22:25 GMT

Dear Checkmates fellows,

I am a little bit unsure about the difference of these values regarding memory. I have take these from the sk90860 - "How to configure SNMP on Gaia OS" - section "VI-1-B - memory".

What is the difference:

RAM - Real Total
RAM - Real Active
RAM - Real Free
RAM - Virtual Total
RAM - Virtual Active
Hmem fails
System Kmem fails

Many thanks for clarification.

Best regards,
Christian

Re: Difference in RAM values, like Real vs. Virtual

_Val_ — Wed, 14 Apr 2021 12:37:50 GMT

These are OS memory report numbers. I believe SK you mentioned does have explanation for the each item (omitting unnecessary details:

Required Information	OID Description
RAM - Real Total	Total real memory in bytes. Memory used by applications.
RAM - Real Active	Active real memory in bytes (memory used by applications that is not cached to the disk).
RAM - Real Free	Free memory in bytes available for applications.
RAM - Virtual Total	The size in bytes of the virtual-memory working segment pages.
RAM - Virtual Active	The size in bytes of the virtual-memory working segment pages that have actually been touched.
Hmem fails	Hash memory allocation failures.
System Kmem fails	System Kernel memory (SMEM) allocation failures.

You should also be able to get more info about each position on Linux resources, for example: https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/6/html/deployment_guide/s1-sysinfo-memory-usage

Re: Difference in RAM values, like Real vs. Virtual

_Val_ — Wed, 14 Apr 2021 12:39:12 GMT

To add, most concerns should be about allocation failures (hmem fails, system kmem fails) and swap status. By no means your GWs should ever swap.