How to determine total, free, available memory on ESX hypervisor via pyvmomi or cli?

Question

I am looking for ESX/ESXi specific commands/samples pyvmomi APIs to determine system memory information on the hypervisor - free/total/used.

score 6 · Answer 1 · answered Mar 21 '20 at 18:45

Run ESXi host command

vsish -e get /memory/comprehensive

Raw output

Comprehensive {
   Physical memory estimate:12454784 KB
   Given to VMKernel:12454784 KB
   Reliable memory:0 KB
   Discarded by VMKernel:1580 KB
   Mmap critical space:0 KB
   Mmap buddy overhead:3084 KB
   Kernel code region:18432 KB
   Kernel data and heap:14336 KB
   Other kernel:1421360 KB
   Non-kernel:120036 KB
   Reserved memory at low addresses:59900 KB
   Free:10875956 KB
}

Format

vsish -e get /memory/comprehensive | sed 's/:/ /' | awk '
    /Phys/ { phys = $(NF-1); units = $NF; width = length(phys) }
    /Free/ { free = $(NF-1) }
    END    { print width, units, phys, phys-free, free }' |
    while read width units phys used free; do
        printf "Phys %*d %s\n" $width $phys $units
        printf "Used %*d %s\n" $width $used $units
        printf "Free %*d %s\n" $width $free $units
    done

Output

Phys 12454784 KB
Used  1580564 KB
Free 10874220 KB

score 1 · Answer 2 · answered Nov 19 '19 at 22:16

As there is also CLI mentioned in the question title, I'll add how one can retrieve memory usage via ESXi's command line. I used ESXi 6.7, but this should work since version ESX 4.0 as only the performance gathering is run on the ESXi host.

In ESXi SSH session run below to gather performance data:

# Source: https://kb.vmware.com/s/article/1004953
esxtop -b -n 1 > /tmp/perf.csv

SCP the performance data to a Linux machine.

Run the script below in a Linux terminal in a folder that contains the perf.csv:

printf "Total Memory: "; \
line_overall_mem="$(head -1 perf.csv | tr "," "\12" | grep -in "Machine MBytes" | cut -d ":" -f1)"; \
tail -1 perf.csv | tr "," "\12" | sed -n "${line_overall_mem}p" | sed 's/"//g'; \
printf "Free Memory: "; \
line_free_mem="$(head -1 perf.csv | tr "," "\12" | grep -in 'Memory\\Free MBytes' | cut -d ":" -f1)"; \
tail -1 perf.csv | tr "," "\12" | sed -n "${line_free_mem}p" | sed 's/"//g'

Output should be something like:
```
Total Memory: 24566
Free Memory: 7519
```

I've got couple free ESXis running with 6.7 U2. VMware's hardware compatibility list actually states that my hardware is only compatible with ESXi 4.1, but they're still running fine.

I've got the above and more information automatically written to a NFS share once a day. From the NFS share the information gets published via Linux VM web server.

score 0 · Answer 3 · answered Mar 22 '17 at 05:29

I found the answer at:

https://gist.github.com/deviantony/5eff8d5c216c954973e2

Specifically, these lines:

    memoryCapacity = hardware.memorySize
    memoryCapacityInMB = hardware.memorySize/MBFACTOR
    memoryUsage = stats.overallMemoryUsage
    freeMemoryPercentage = 100 - (
        (float(memoryUsage) / memoryCapacityInMB) * 100
    )

How to determine total, free, available memory on ESX hypervisor via pyvmomi or cli?

3 Answers3