Powershell / VMware

VMware Storage Performance Testing Suite

Tapas Kumar MahantaLeave a comment

ESXi hosts provide fio, ioping, and esxtop for storage benchmarking directly from CLI, while vCenter PowerCLI aggregates performance across clusters/datastores. This script suite generates IOPS, latency, and throughput charts viewable in Confluence/HTML dashboards.​

Core Testing Engine (fio-perf-test.sh)

Purpose: Run standardized fio workloads (4K random, 64K seq) on VMFS/NFS datastores.

bash#!/bin/bash
# fio-perf-test.sh - Run on ESXi via SSH
DATASTORE="/vmfs/volumes/$(esxcli storage filesystem list | grep -v Mounted | head -1 | awk '{print $1}')"
TEST_DIR="$DATASTORE/perf-test"
FIO_TEST="/usr/lib/vmware/fio/fio"

mkdir -p $TEST_DIR
cd $TEST_DIR

cat > fio-random-4k.yaml << EOF
[global]
ioengine=libaio
direct=1
size=1G
time_based
runtime=60
group_reporting
directory=$TEST_DIR

[rand-read]
rw=randread
bs=4k
numjobs=4
iodepth=32
filename=testfile.dat

[rand-write]
rw=randwrite
bs=4k
numjobs=4
iodepth=32
filename=testfile.dat
EOF

# Run tests
$FIO_TEST fio-random-4k.yaml > /tmp/fio-4k-results.txt
$FIO_TEST --name=seq-read --rw=read --bs=64k --size=4G --runtime=60 --direct=1 --numjobs=1 --iodepth=32 $TEST_DIR/testfile.dat >> /tmp/fio-seq-results.txt

# Cleanup
rm -rf $TEST_DIR/*
echo "$(hostname),$(date),$(grep read /tmp/fio-4k-results.txt | tail -1 | awk '{print $3}'),$(grep IOPS /tmp/fio-4k-results.txt | grep read | awk '{print $2}')" >> /tmp/storage-perf.csv

Cron Schedule: 0 2 * * 1 /scripts/fio-perf-test.sh (weekly baseline).​

vCenter PowerCLI Aggregator (StoragePerf.ps1)

Purpose: Collects historical perf + runs live esxtop captures across all hosts.

powershell# StoragePerf.ps1 - vCenter Storage Performance Dashboard
Connect-VIServer vcenter.example.com

$Report = @()
$Clusters = Get-Cluster

foreach ($Cluster in $Clusters) {
    $Hosts = Get-VMHost -Location $Cluster
    foreach ($Host in $Hosts) {
        # Live esxtop data (requires esxtop installed)
        $Esxtop = Invoke-VMScript -VM $Host -ScriptText {
            esxtop -b -a -d 30 | grep -E 'DAVG|%LAT|IOPS' | tail -20
        } -GuestCredential (Get-Credential)

        # Historical datastore stats
        $Datastores = Get-Datastore -VMHost $Host
        foreach ($DS in $Datastores) {
            $Perf = $DS | Get-Stat -Stat "datastore.read.average","datastore.write.average" -MaxSamples 24 -Interval Min | 
                    Select @{N='Time';E={$_.Timestamp}}, @{N='ReadKBps';E={[math]::Round($_.Value,2)}}, @{N='WriteKBps';E={[math]::Round($_.Value,2)}}
            
            $Report += [PSCustomObject]@{
                Host = $Host.Name
                Datastore = $DS.Name
                FreeGB = [math]::Round($DS.FreeSpaceGB,1)
                ReadAvgKBps = ($Perf.ReadKBps | Measure -Average).Average
                WriteAvgKBps = ($Perf.WriteKBps | Measure -Average).Average
                EsxtopLatency = ($Esxtop | Select-String "DAVG" | Select-Object -Last 1).ToString().Split()[2]
            }
        }
    }
}

# Export CSV for charts
$Report | Export-Csv "StoragePerf-$(Get-Date -f yyyy-MM-dd).csv" -NoTypeInformation

# Generate HTML dashboard
$Report | ConvertTo-Html -Property Host,Datastore,FreeGB,ReadAvgKBps,WriteKBps,EsxtopLatency -Title "Storage Performance" | 
    Out-File "storage-dashboard.html"

Performance Chart Generator (perf-charts.py)

Purpose: Converts CSV data to interactive Plotly charts for Confluence.

python#!/usr/bin/env python3
# perf-charts.py - Generate HTML charts from CSV
import pandas as pd
import plotly.express as px
import plotly.graph_objects as go
from plotly.subplots import make_subplots
import sys

df = pd.read_csv(sys.argv[1])

# IOPS vs Latency scatter
fig1 = px.scatter(df, x='ReadAvgKBps', y='EsxtopLatency', 
                 size='FreeGB', color='Host', hover_name='Datastore',
                 title='Storage Read Performance vs Latency',
                 labels={'ReadAvgKBps':'Read KBps', 'EsxtopLatency':'Avg Latency (ms)'})

# Throughput bar chart
fig2 = px.bar(df, x='Datastore', y=['ReadAvgKBps','WriteAvgKBps'], 
              barmode='group', title='Read/Write Throughput by Datastore')

# Combined dashboard
fig = make_subplots(rows=2, cols=1, subplot_titles=('IOPS vs Latency', 'Read/Write Throughput'))
fig.add_trace(fig1.data[0], row=1, col=1)
fig.add_trace(fig2.data[0], row=2, col=1)
fig.add_trace(fig2.data[1], row=2, col=1)

fig.write_html('storage-perf-dashboard.html')
print("Charts saved: storage-perf-dashboard.html")

Usage: python3 perf-charts.py StoragePerf-2025-12-28.csv

Master Orchestrator (storage-benchmark.py)

Purpose: Runs fio tests on all ESXi hosts + generates dashboard.

python#!/usr/bin/env python3
import paramiko
import subprocess
import pandas as pd
from datetime import datetime

ESXI_HOSTS = ['esxi1.example.com', 'esxi2.example.com']
VCENTER = 'vcenter.example.com'

def run_fio(host):
    ssh = paramiko.SSHClient()
    ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
    ssh.connect(host, username='root', password='your-esxi-password')
    
    # Copy & run fio script
    stdin, stdout, stderr = ssh.exec_command('wget -O /tmp/fio-test.sh https://your-confluence/scripts/fio-perf-test.sh && chmod +x /tmp/fio-test.sh && /tmp/fio-test.sh')
    result = stdout.read().decode()
    ssh.close()
    return result

# Execute tests
perf_data = []
for host in ESXI_HOSTS:
    print(f"Testing {host}...")
    run_fio(host)
    perf_data.append({'Host': host, 'TestTime': datetime.now()})

# Pull PowerCLI report
subprocess.run(['pwsh', '-File', 'StoragePerf.ps1'])

# Generate charts
subprocess.run(['python3', 'perf-charts.py', f'StoragePerf-{datetime.now().strftime("%Y-%m-%d")}.csv'])

print("Storage benchmark complete. View storage-perf-dashboard.html")

Confluence Chart Embedding

HTML Macro (paste storage-perf-dashboard.html content):

text{html}

{html}

CSV Table with Inline Charts:

text||Host||Datastore||Read IOPS||Latency||Chart||
|esxi1|datastore1|2450|2.3ms|![Read IOPS|width=150px,height=100px](storage-esxi1.png)|

Automated Dashboard Cronjob

bash#!/bin/bash
# /etc/cron.d/storage-perf
# Daily 3AM: Test + upload to Confluence
0 3 * * * root /usr/local/bin/storage-benchmark.py >> /var/log/storage-perf.log 2>&1

Output Files:

  • /tmp/storage-perf.csv → Historical trends
  • storage-perf-dashboard.html → Interactive Plotly charts
  • /var/log/storage-perf.log → Audit trail

Sample Output Charts

Expected Results (Tintri VMstore baseline):

textDatastore: tintri-vmfs-01
4K Random Read: 12,500 IOPS @ 1.8ms
4K Random Write: 8,200 IOPS @ 2.4ms
64K Seq Read: 450 MB/s
64K Seq Write: 380 MB/s

Pro Tips & Alerts

text☐ Alert if Latency > 5ms: Add to PowerCLI `if($EsxtopLatency -gt 5) {Send-MailMessage}`
☐ Tintri-specific: Add `esxtop` filter for Tintri LUN paths
☐ NFS tuning: Test with `nfs.maxqueuesize=8` parameter
☐ Compare baselines: Git commit CSV files weekly

Run First: python3 storage-benchmark.py --dry-run to validate hosts/configs.​

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