Nutanix Emergency VM Rescue Bash Toolkit

Introduction

Every environment faces moments of failure. Whether from guest corruption, misconfigurations, or broken updates, virtual machines sometimes need urgent rescue. This guide offers a pre-built Bash-based emergency toolkit using acli to snapshot VMs, reassign NICs, attach recovery ISOs, and power cycle problematic VMs.

My Personal Repository on GitHub

Nutanix Repository on GitHub

Diagram: Rescue Toolkit Flow

Rescue Toolkit Functions

1. Snapshot current VM state
2. Detach all NICs (useful for network isolation)
3. Attach ISO for repair
4. Power off/on cycle

Bash Script: nutanix_vm_rescue.sh

#!/usr/bin/env bash
set -euo pipefail

vm="$1"
iso_image="CentOS-Rescue.iso"
log="/var/log/nutanix_rescue.log"

echo "[$(date)] Starting rescue for $vm" | tee -a "$log"

# Step 1: Snapshot
snap_name="${vm}_rescue_$(date +%Y%m%d%H%M)"
acli vm.snapshot_create "$vm" snapshot_name="$snap_name"
echo "Snapshot created: $snap_name" | tee -a "$log"

# Step 2: Power off
acli vm.off "$vm"
echo "VM powered off" | tee -a "$log"

# Step 3: Detach NICs
acli vm.nic.delete_all "$vm"
echo "All NICs detached" | tee -a "$log"

# Step 4: Attach ISO
acli vm.cdrom_update "$vm" clone_from_image="$iso_image"
echo "Attached ISO: $iso_image" | tee -a "$log"

# Step 5: Power on VM
acli vm.on "$vm"
echo "Rescue boot initiated" | tee -a "$log"

Usage Example

./nutanix_vm_rescue.sh app01

Tips for Rescue Operations

• Preload known-good ISO images in the image service
• Always create a snapshot before any destructive action
• Detach NICs to prevent boot loop or DHCP issues
• Reattach network or restore from snapshot after inspection

Optional Enhancement: Slack or Email Alert

echo "Rescue started for $vm" | mailx -s "Nutanix VM Rescue Triggered" ops@example.com

Summary

The Nutanix Emergency VM Rescue Toolkit helps you act fast when systems go sideways. Whether it’s attaching an ISO, detaching NICs, or just grabbing a safe snapshot, this script builds a first-response automation layer for unstable VMs.

External Documentation:

• Nutanix acli VM Snapshot & Boot Commands