How does the rsp probe calculate memory and disk QOS metrics

Products

• DX Unified Infrastructure Management (Nimsoft / UIM)
• CA Unified Infrastructure Management On-Premise (Nimsoft / UIM)
• CA Unified Infrastructure Management SaaS (Nimsoft / UIM)

Issue/Introduction

We need to know how to check all of the rsp metrics.  rsp will collect data with USAGE and PERCENT. We need to cross check if this calculation is correct. Please provide steps to check all of the metrics below:

• Disk Memory
• Physical Memory
• Swap

Environment

• Component: UIMRSP

Resolution

The qos metrics collected by rsp probe are QOS_DISK_USAGE and QOS_DISK_USAGE_PERC.

The rsp probe uses the following formulas for the different qos metrics in Windows and Linux/Unix.

LINUX/UNIX

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In Linux/UNIX environments, the following commands are executed by the rsp probe:

df -P -k -l (Linux)

df -k –l (Solaris)

df -P –k (AIX)
 

Filesystem	1024-blocks/size	Used	Available	Capacity	Mounted on
/dev/mapper/rhel-root	52403200	4721904	47681296	10%	/
devtmpfs	4072044	0	4072044	0%	/dev
tmpfs	4087720	24	4087696	1%	/dev/shm
tmpfs	4087720	320688	3767032	8%	/run
tmpfs	4087720	0	4087720	0%	/sys/fs/cgroup
/dev/mapper/sdbvg-loddisk2	62879748	32944	62846804	1%	/loddisk2
/dev/mapper/rhel-home	43093444	35580	43057864	1%	/home
/dev/sda1	1038336	163488	874848	16%	/boot
tmpfs	817548	0	817548	0%	/run/user/990
tmpfs	817548	12	817536	1%	/run/user/42
tmpfs	817548	0	817548	0%	/run/user/0

 
QOS_DISK_USAGE (Disk I/O rate MB)                =     (Used)/1024
QOS_DISK_USAGE_PERC(Disk Usage%)             =     (Used/1024-blocks) *100
For instance of /dev/mapper/rhel-root 
QOS_DISK_USAGE (Disk I/O rate MB)                =     4721904/1024
QOS_DISK_USAGE_PERC(Disk Usage%)             =     (4721904/52403200) *100

WINDOWS:

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Get From Resource Monitor:

QOS_DISK_USAGE (Disk I/O rate MB)  =  Total Space  - AvailableSpace;
QOS_DISK_USAGE_PERC(Disk Usage%)    =  (Total Space  - AvailableSpace)/ Total Space 

For instance of E drive above:

QOS_DISK_USAGE (Disk I/O rate MB)  =  61439  - 52052;
QOS_DISK_USAGE_PERC(Disk Usage%)    =  (61439  - 52052)/ 61439 * 100

Memory /Physical Memory /Swap

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LINUX

Run Command (Linux) : cat /proc/meminfo  (vmstat  for solaris)
 
MemTotal:        8175444 kB
MemFree:           743656 kB
MemAvailable:   1433636 kB
Buffers:                6400 kB
Cached:               1156064 kB
SwapCached:            0 kB
SwapTotal:         8257532 kB
SwapFree:          8257532 kB

QOS_MEMORY_SWAP (SwapUsed MB) = (SwapTotal - SwapFree) / 1024
QOS_MEMORY_PHYSICAL (Physical Memory Used MB) = (MemTotal - MemFree) /1024
QOS_MEMORY_USAGE (Total Memory Used MB) = (MemTotal - MemFree + SwapUsed) /1024
QOS_MEMORY_PERC_USAGE (Total Memory Used %)=(Total Memory Used/Total Memory) *100         //  Total Memory = (MemTotal + SwapTotal) / 1024
QOS_PHYSICAL_MEMORY_PERC_USAGE (Physical Memory Used %) = (Physical Memory Used/Physical Memory) * 100   // Physical Memory = MemTotal / 1024          

WINDOWS:

Get From Resource Monitor:

QOS_MEMORY_SWAP (SwapUsed MB) = Total - PhysicalMemory
QOS_MEMORY_PHYSICAL (Physical Memory Used MB) = Physical Memory
QOS_MEMORY_USAGE (Total Memory Used MB) = Physical Memory -Available
QOS_MEMORY_PERC_USAGE (Total Memory Used %)= (Physical Memory –Available) /Total
QOS_PHYSICAL_MEMORY_PERC_USAGE (Physical Memory Used %) = (Physical Memory –Available)/Physical Memory * 100 

Additional Information

The meminfo file reports the memory in KB and the probes report the QOS Metricx in MB hence we divide by 1024 in the above formulas.

You will likley see a small difference in the values in meminfo and the QOS metric. Memory usage is a constantly shifting value and the probe will have collected at a slightly different time to when you viewed the meminfo file.