How does RSP calculate Memory and Disk

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Article ID: 130591

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Updated On:

Products

DX Infrastructure Management NIMSOFT PROBES

Issue/Introduction

We need to know how to check the total of rsp metric. As monitor, rsp will collect data with USAGE and PERCENT.

We need to cross check if this calculation is correct. Please provide step to check all of metrics below:

Disk Memory
Physical Memory
Swap

Environment

Release:
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


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  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:


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 driver 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

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 reports the QOS Metric in MB hence we divide by 1024 in the above formulas.

You will very likely 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.

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