What are the steps to troubleshoot virtual machine boot issues?

Here's a general perspective: - Identify Virtualization Software - Using Management Console - Using Command Line Interface (CLI) - Power On or Resume VM - Handling Unresponsive VM - Check for Error Messages - Resource Availability - Update Virtualization Software - Review VM Configuration - Consider System Reboot - Documentation and Support

Before we attempt to fix boot issue we need to understand boot sequence: BIOS:POST(Power ON self Test), Loads Master Boot record, detect & select boot device. MBR: Loads Grand unified boot loader. GRUB: Executes kernel, load supported libraries. KERNEL: Executes systemd as first process in userspace. Systemd: Run default target file. Runlevel: Reads /etc/inittab to boot in appropriate runlevel also, executes /etc/rc.d/rc.sysinit. Now if you go through the stages mentioned above the VM boot issues could be caused due to: 1. POST check fail due to HW issue 2. Boot device not being detected 3. Corrupted or Missing GRUB 4. Corrupted OS where target files and system init files are missing.

Certainly! Here's a condensed version: 1. **Verify Basics:** - Check host machine and disk space. - Confirm VM configuration. 2. **Inspect Logs:** - Check hypervisor logs for errors. 3. **Review Boot Configuration:** - Confirm VM boot order and disk. - Check BIOS/UEFI settings. 4. **Safe Mode/Recovery:** - Boot into safe mode or recovery mode. 5. **OS Integrity:** - Verify OS file integrity. - Repair or reinstall OS if needed. 6. **Bootloader and Storage:** - Check bootloader configuration. - Verify storage connectivity. 7. **Snapshots/Checkpoints:** - Consider reverting to a previous state. - Be cautious to avoid data loss.

Create and access a Repair VM. Verify that the OS partition is active. Fix the missing reference on the BCD store. Rebuild the VM.

Here's a general perspective: - Identify Virtualization Software - Using Management Console - Using Command Line Interface (CLI) - Power On or Resume VM - Handling Unresponsive VM - Check for Error Messages - Resource Availability - Update Virtualization Software - Review VM Configuration - Consider System Reboot - Documentation and Support

1. Open the virtualization management tool 2. Locate the virtual machine 3. Identify the virtual machine 4. Access the logs: Right-click on the virtual machine and select the option to view or access its logs. This option may be named "Logs," "View Logs," or something similar. 5. Analyze the logs: Once you have accessed the logs, review them for any error messages, warnings, or other relevant information. Pay attention to timestamps, error codes, and any recurring patterns that may help identify the root cause of any issues.

The next step is to review the logs of your VM to look for any errors or warnings that might indicate the cause of the boot issue. You can access the logs from the management console or the command line interface of your virtualization software, or from the guest operating system (OS) of your VM if it is accessible. The logs can provide useful information, such as the boot sequence, the drivers, the services, and the applications that are loaded or failed during the boot process. You can also compare the logs with a working VM to identify any differences or anomalies.

An example I have seen is play is to confirm that the VM is not in a clustered disk group and that the conditions for creating a clustered virtual disks is met.

From the OS perspective, consider using emergency mode for linux or safe mode for windows if the normal booting process does not work. This would allow access to more logs and os settings to be checked.

There are different steps to troubleshoot virtual machine boot issues depending on the cause and the type of the virtual machine. Some common steps are: • Make sure that the host server has enough resources available to start the virtual machine, such as memory, CPU, and disk space • Verify that the physical disk or the external storage array where the virtual machine resides is functioning properly and accessible by the host server • Use a Windows troubleshooting VM or a recovery VM to access and repair the OS disk of the affected virtual machine • Check the boot configuration data (BCD) store and the boot sector of the OS disk for any corruption or missing references • Run CHKDSK or other tools to fix any errors on the OS

If the issue is been caused by a corrupt file in the boot process 1. Get the file from a good working VM and replace with the faulty one 2. Repair the registry key that is faulty (always backup the registry before doing this )

Two additional items that can affect VM boot up: 1) Make sure the bios type is set correctly (legacy vs uefi) 2) Check for secure boot settings

1. Connect to the Vmware management console 2. Check if there is any need for snapshot consolidation 3. Check the resource utilization of the VM(Memory, Cpu and Disk) and Datastore hosting the VM 4. Check if there are pending updates that requires restart of the VM 5.

1. Open the virtualization management tool 2. Locate the virtual machine 3. Identify the virtual machine 4. Access the settings: Right-click on the virtual machine and select the option to access or edit its settings. This option may be named "Settings," "Edit Settings," or something similar. 5. Review the settings: Once you have accessed the settings, go through each category or section to review the configurations. This includes virtual hardware settings like CPU, memory, storage, network adapters, and other devices. 6. Ensure correctness: Verify that the settings are correctly configured according to your requirements and best practices.

Verify that your boot disk is not full Examine your virtual machine instance's serial port output. ... Enable interactive access to the serial console Verify that your disk has a valid file system. Verify that the disk has a valid master boot record (MBR).

To restore the VM in Azure 1. Check to see if you have backup and restore from last good backup. 2. Boot the VM up in a nested hyper-v 3. Restore from last good known configuration

If a linux server does not boot normaly, troubleshooting can be done from emergency target or sinlge user mode to view more logs and access other available commands.

epairing VM files can vary depending on the virtualization platform being used. However, here are some general steps to repair VM files: 1. Shut down the virtual machine./ 2. Take a backup 3. Identify the corrupted files 4. Use built-in repair tools 5. Attempt manual repair: If there are no built-in repair tools, you can attempt manual repair by recreating or replacing the corrupted files. 6. Verify the repaired files: After repairing or replacing the corrupted files, verify their integrity and ensure that the virtual machine can be started without any issues. 7. Test the virtual machine: Power on the virtual machine and test its functionality to ensure that the repairs were successful and that the VM is operating as expected.

You should scan for malware by using an antivirus or an anti-malware software on a bootable CD-ROM or a write protected USB drive. Otherwise the virus can hop onto the drive before it gets a chance to scan.

1. Install or update antivirus or anti-malware software: 2. Perform a full system scan 3. Follow the software prompts: During the scan, the antivirus or anti-malware software will identify and quarantine or remove any detected malware. Follow the prompts provided by the software to take the necessary actions. 4. Review scan results: Once the scan is complete, review the scan results provided by the software. 5. Update security software and patches: Regularly update your antivirus or anti-malware software to ensure it has the latest virus definitions and security patches. 6. Utilize bootable CD-ROM or USB drive: In some cases, malware may be difficult to detect or remove when the virtual machine's operating system is running.

In my recent certification they described so coherently. To scan for malware in the context of Information Security (ISC), deploy reputable antivirus or anti-malware software. Regularly update the malware definitions and conduct thorough scans across the system, including files, applications, and network traffic. Additionally, consider implementing intrusion detection systems (IDS) and intrusion prevention systems (IPS) to fortify the security posture against potential threats. Continuous monitoring and timely response to security alerts play a pivotal role in maintaining a resilient ISC framework.

Even in test environments it is recommended to verify you have been back up all relevant virtual machines. RAID and snapshots are not considered backups. You should backup your data to an external location to prevent data loss in catastrophic events in your company (fire, earthquake, etc).

Restore from the last VM backup from the daily routine backup. As a IT manager, I work in a virtual environment in a banking industry

Regarding VMware backups, you’ll want to test regularly that you can restore from your backups. Backups are only useful if they work when you need them.

Additionally, it is important to identify where the failure is in the boot process. Knowledge of the boot process helps in streamlining the troubleshooting based on error and the point of failure. Depending on where the error lies- for instance, the error occurs at POST phase, it could mean issue lies within the host machine where the VM is hosted..

depending on the senario its always important to get as much info before starting to work. fx when the the error occur and did any changes happen before the error. All these questions can help solve the issue faster why a VM will not boot. Patching a server that could after reboot BSOD a VM is one instance. hypervisor update can have VMs break if something special is setup or something is out of support in that server. getting info is important

Stop using VMs! At the very least you should be using containers! They offer a streamlined alternative to traditional virtual machines (VMs). Unlike VMs, containers share the host operating system's kernel, leading to faster startup times and reduced resource overhead. This makes containers more resilient in scenarios where quick booting and responsiveness are critical. Troubleshooting containerized applications is often simpler due to their encapsulated nature. Containers promote scalability and agility, enabling rapid deployment and scaling of applications, which is particularly advantageous in dynamic and evolving environments.

In a corporative scenario It's very important to know if the VM is a regular one or is being provisioned and how. Depending on that we have to check the storage (Check logs) or the network (latency, DNS pointing to a different provisioning server, PXE issues, etc.)