A Quick Guide to Installing and Using lsdoctor for vCenter Troubleshooting

The lsdoctor tool is designed to help diagnose and resolve common issues related to the VMware vCenter Lookup Service. Here’s a quick overview of how to install, launch, and utilize its various functions effectively.

🛠️ Installation

To get started with lsdoctor, download the ZIP file provided and transfer it to the target node using a file transfer tool like WinSCP. If you encounter issues connecting to a vCenter Appliance using WinSCP, refer to VMware’s documentation for troubleshooting.

Steps:

  1. Transfer the ZIP file to your vCenter node.
  2. Extract the ZIP file:
    • VCSA (vCenter Server Appliance):
bash
unzip lsdoctor.zip

Key Functions of lsdoctor

The lsdoctor tool comes with various options for checking and fixing issues in the vCenter Lookup Service:

  1. --lscheck (-l): Checks for common issues without making changes.
    • Usage: python lsdoctor.py -l
    • Follow-up: Review the JSON report for findings.
  2. --pscHaUnconfigure (-p): Removes a PSC High Availability configuration.
    • Usage: python lsdoctor.py -p
    • Follow-up: Restart services and repoint your vCenter servers.
  3. --stalefix (-s): Cleans up stale configurations from older upgrades.
    • Usage: python lsdoctor.py -s
    • Follow-up: Restart services and re-register external solutions.
  4. --trustfix (-t): Resolves SSL trust issues in the Lookup Service.
    • Usage: python lsdoctor.py -t
    • Follow-up: Restart services on all nodes.
  5. --solutionusers (-u): Recreates solution users for the node.
    • Usage: python lsdoctor.py -u
    • Follow-up: Restart services on the node.
  6. --rebuild (-r): Rebuilds service registrations for the node.
    • Usage: python lsdoctor.py -r
    • Follow-up: Restart services and re-register external solutions.

More info in KB

Critical Security Alert: Update to Fixed Version 8.0 U3d Immediately

Urgent Notice from VMware by Broadcom

VMware has announced that the security patches released on September 17, 2024, intended to address CVE-2024-38812, did not fully mitigate the vulnerability. As a result, all customers are strongly advised to update to the latest version, 8.0 U3d, immediately. Patches for the 8.0 U2 line are also available to address this issue.

This urgent advisory applies to all vCenter Server users, as the newly identified vulnerabilities pose a significant security risk. Notably, two critical vulnerabilities were reported in vCenter Server, including a heap-overflow vulnerability and a privilege escalation vulnerability. These have been responsibly reported to VMware, which has now provided updates to address them.

Key Vulnerability: Heap-Overflow in vCenter Server (CVE-2024-38812)

Vulnerability Description:

A critical heap-overflow vulnerability was discovered in vCenter Server, specifically in its implementation of the DCERPC protocol. The issue has been assigned CVE-2024-38812 and carries a CVSSv3 base score of 9.8, placing it in the Critical severity range.

Known Attack Vectors:

This vulnerability can be exploited by a malicious actor who has network access to the vCenter Server. By sending a specially crafted network packet, the attacker could trigger the heap-overflow, potentially leading to remote code execution (RCE) on the affected system.

Why You Should Patch Now

This vulnerability could allow attackers to gain control over your vCenter Server environment, putting your infrastructure at risk for unauthorized access, data breaches, or service disruptions. Given the widespread use of vCenter Server for managing virtual environments, this threat is extremely serious, especially for businesses relying on VMware for critical operations.

Patch Availability

The new patches, which can be found in the Response Matrix, have been made available for both the 8.0 U3, 8.0 U2 and 7.0 U3 versions of vCenter Server. Customers should apply the new patches immediately to ensure their systems are protected.

What to Do:

  1. Check your version: Identify if your vCenter Server version is affected.
  2. Apply the patches: Use the Response Matrix provided by VMware to download and install the necessary updates.
  3. Follow VMware’s best practices: Regularly update your systems, review security advisories, and apply patches as soon as they are released to minimize security risks.

Mount VMware-vCenter-Server-Appliance-8.0.3.00400-24322831-patch-FP.iso to VCSA VM. Log in to the appliance shell as a user with super administrative privileges (for example, root) and run the following commands:

# To stage the ISO:
software-packages stage --iso

# To see the staged content:
software-packages list --staged

# To install the staged rpms:
software-packages install --staged

VMware vCenter Server 8.0 Update 3c: Fixing vSphere Client Idle Session Issue

VMware has released vCenter Server 8.0 Update 3c, bringing several key improvements and bug fixes. Among these, one notable issue addressed in this release relates to the vSphere Client’s behavior when left idle for extended periods.

PR 3439359: vSphere Client Session Becomes Unresponsive After 50 Minutes of Inactivity

In previous versions, particularly starting from vSphere 8.0 Update 3b, users encountered a frustrating issue with the vSphere Client. If a session remained idle for more than 50 minutes, the client would become unresponsive, making it impossible to log in or log out. Attempting to resume work in the same browser would yield no results unless all browser cookies were cleared. This was not only an inconvenience but also a disruption for administrators managing their vSphere environments.

Cause of the Issue: Apache Tomcat 9.0.91 Upgrade

The root of the problem was traced back to an upgrade to Apache Tomcat 9.0.91, introduced in vSphere 8.0 Update 3b. This upgrade brought with it a change in the default value of the property org.apache.catalina.connector.RECYCLE_FACADES. Previously set to FALSE, this value was altered to TRUE, causing sessions to become invalid after extended inactivity. This meant that any session left idle for over 50 minutes would not properly refresh, effectively locking the user out until they manually cleared cookies from their browser.

Links:

Intel Skylake CPUs Reaching End of Support in Future vSphere Releases after 8.x

As the IT industry continues to evolve, so do the platforms and hardware that support our digital infrastructure. One significant upcoming change is related to Intel’s Skylake generation of processors, which has entered the End of Servicing Update (ESU) and End of Servicing Lifetime (EOSL) phase. By December 31, 2023, Intel will officially stop providing updates for Skylake server-class processors, including the Xeon Scalable Processors (SP) series. This change is set to impact future VMware vSphere releases, as VMware plans to discontinue support for Intel Skylake CPUs in its next major release following vSphere 8.x.

Why Skylake CPUs are Being Phased Out

Intel’s Skylake architecture, introduced in 2015, has been widely adopted in server environments for its balance of performance and power efficiency. The Xeon Scalable Processor series, which is part of the Skylake generation, has been foundational in many data centers around the world. However, as technology progresses, older generations of processors become less relevant in the context of modern workloads and new advancements in CPU architectures.

Impact on VMware vSphere Users

With VMware announcing plans to drop support for Skylake CPUs in a future major release after vSphere 8.x, organizations relying on these processors need to start planning for hardware refreshes. As VMware’s virtualization platform evolves, it is optimized for more modern CPU architectures that offer enhanced performance, security, and energy efficiency.

More info CPU Support Deprecation and Discontinuation In vSphere Releases

vSphere Client Instability and Session Timeouts After vCenter Server 8.0.3.00200 Upgrade: How to Resolve

After upgrading to vCenter Server 8.0.3.00200, some users have reported issues with the vSphere Client becoming unstable, particularly after long periods of session idleness (typically 1-2 hours). This instability may manifest in a variety of ways, including session timeouts, continuous loading indicators, and errors when browsing the inventory.

Root Cause

The root cause of this instability appears to be related to a misconfiguration in how the vSphere Client handles facade recycling within the Apache Catalina Connector.

Solution: Updating the Catalina Configuration

root@vcsa-home [ ~ ]# cp /usr/lib/vmware-vsphere-ui/server/conf/catalina.properties /root/catalina.properties.bak

root@vcsa-home [ ~ ]# echo "org.apache.catalina.connector.RECYCLE_FACADES=false" >> /usr/lib/vmware-vsphere-ui/server/conf/catalina.properties

root@vcsa-home [ ~ ]# service-control --restart vsphere-ui

VMSA-2024-0019: Critical VMware vCenter Server Vulnerabilities (CVE-2024-38812, CVE-2024-38813) Addressed

VMware has released an important security advisory, VMSA-2024-0019, detailing updates for VMware vCenter Server that address two significant vulnerabilities: a heap-overflow vulnerability (CVE-2024-38812) and a privilege escalation vulnerability (CVE-2024-38813). Both of these vulnerabilities could have severe implications if exploited, making it crucial for administrators to apply the necessary patches promptly.

Heap-Overflow Vulnerability (CVE-2024-38812)

Description: The first vulnerability, identified as CVE-2024-38812, is a heap-overflow vulnerability found in the vCenter Server’s implementation of the DCERPC protocol. This issue has been classified by VMware as Critical, with a maximum CVSSv3 base score of 9.8, indicating the potential for severe impact.

Known Attack Vectors: A malicious actor with network access to the vCenter Server can exploit this vulnerability by sending a specially crafted network packet. Successful exploitation could lead to remote code execution (RCE), allowing the attacker to execute arbitrary code on the vCenter Server with potentially full system privileges. This level of access could be used to disrupt services, exfiltrate sensitive data, or further compromise the virtual environment.

Privilege Escalation Vulnerability (CVE-2024-38813)

Description: The second vulnerability, CVE-2024-38813, is a privilege escalation flaw within the vCenter Server. VMware has rated this issue as Important, with a CVSSv3 base score of 7.5. While not as severe as the heap-overflow vulnerability, it still poses a significant risk.

Known Attack Vectors: An attacker with network access to the vCenter Server can exploit this vulnerability by sending a specially crafted network packet. If successful, the attacker could escalate their privileges to root, gaining full administrative control over the vCenter Server. This level of access could enable the attacker to make unauthorized changes, access sensitive information, or disrupt the entire virtual infrastructure.

More info VMSA-2024-0019:VMware vCenter Server updates address heap-overflow and privilege escalation vulnerabilities (CVE-2024-38812, CVE-2024-38813)

Add nConnect Support to NFS v4.1

Starting with vSphere 8.0 Update 3, nConnect support has been added for NFS v4.1 datastores. This feature enables multiple connections using a single IP address within a session, thereby extending session trunking functionality to that IP. With nConnect, multipathing and nConnect coexist, allowing for more flexible and efficient network configurations.

Benefits of nConnect

Traditionally, vSphere NFSv4.1 implementations create a single TCP/IP connection from each host to each datastore. This setup can become a bottleneck in scenarios requiring high performance. By enabling multiple connections per IP, nConnect significantly enhances data throughput and performance. Here’s a quick overview of the benefits:

  • Increased Performance: Multiple connections can be established per session, reducing congestion and improving data transfer speeds.
  • Flexibility: Customers can configure datastores with multiple IPs to the same server and also multiple connections with the same IP.
  • Scalability: Supports up to 8 connections per IP, enhancing scalability for demanding workloads.

Configuring nConnect

Adding a New NFSv4.1 Datastore

When adding a new NFSv4.1 datastore, you can specify the number of connections at the time of the mount using the following command:

esxcli storage nfs41 add -H <host> -v <volume-label> -s <remote_share> -c <number_of_connections>

By default, the maximum number of connections per session is set to 4. However, this can be increased to 8 using advanced NFS options. Here’s how you can configure it:

  1. Set the maximum number of connections to 8: esxcfg-advcfg -s 8 /NFS41/MaxNConnectConns
  2. Verify the configuration: esxcfg-advcfg -g /NFS41/MaxNConnectConns

The total number of connections used across all mounted NFSv4.1 datastores is limited to 256.

Modifying Connections for an Existing NFSv4.1 Datastore

For an existing NFSv4.1 datastore, the number of connections can be increased or decreased at runtime using the following command:

esxcli storage nfs41 param set -v <volume-label> -c <number_of_connections>

Multipathing and nConnect Coexistence

There is no impact on multipathing when using nConnect. Both NFSv4.1 nConnect and multipaths can coexist seamlessly. Connections are created for each of the multipathing IPs, allowing for enhanced redundancy and performance.

Example Configuration with Multiple IPs

To add a datastore with multiple IPs and specify the number of connections, use:

esxcli storage nfs41 add -H <IP1,IP2> -v <volume-label> -s <remote_share> -c <number_of_connections>

This command ensures that multiple connections are created for each of the specified IPs, leveraging the full potential of nConnect.

Summary

The introduction of nConnect support in vSphere 8.0 U3 for NFS v4.1 datastores marks a significant enhancement in network performance and flexibility. By allowing multiple connections per IP, nConnect addresses the limitations of single connection setups, providing a robust solution for high-performance environments. Whether you’re configuring a new datastore or updating an existing one, nConnect offers a scalable and efficient way to manage your NFS workloads.

https://core.vmware.com/resource/whats-new-vsphere-8-core-storage

Simplified Guide: How to Convert VM Snapshots into Memory Dumps Using vmss2core

Introduction

In the complex world of virtualization, developers often face the challenge of debugging guest operating systems and applications. A practical solution lies in converting virtual machine snapshots to memory dumps. This blog post delves into how you can efficiently use the vmss2core tool to transform a VM checkpoint, be it a snapshot or suspend file, into a core dump file, compatible with standard debuggers.

Step-by-Step Guide

Break down the process into clear, step-by-step instructions. Use bullet points or numbered lists for easier readability. Example:

Step 1: Create and download a virtual machine Snapshots .vmsn and .vmem
  1. Select the Problematic Virtual Machine
    • In your VMware environment, identify and select the virtual machine experiencing issues.
  2. Replicate the Issue
    • Attempt to replicate the problem within the virtual machine to ensure the snapshot captures the relevant state.
  3. Take a Snapshot
    • Right-click on the virtual machine.
    • Navigate to Snapshots → Take snapshot
    • Enter a name for the snapshot.
    • Ensure “Snapshot the Virtual Machine’s memory” is checked
    • Click ‘CREATE’ to proceed.
  4. Access VM Settings
    • Right-click on the virtual machine again.
    • Select ‘Edit Settings’
  5. Navigate to Datastores
    • Choose the virtual machine and click on ‘Datastores’.
    • Click on the datastore name
  6. Download the Snapshot
    • Locate the .vmsn ans .vmem files (VMware Snapshot file).
    • Select the file, click ‘Download’, and save it locally.
Step 2: Locate Your vmss2core Installation
  • For Windows (32bit): Navigate to C:\Program Files\VMware\VMware Workstation\
  • For Windows (64bit): Go to C:\Program Files(x86)\VMware\VMware Workstation\
  • For Linux: Access /usr/bin/
  • For Mac OS: Find it in /Library/Application Support/VMware Fusion/

Note: If vmss2core isn’t in these directories, download it from New Flings Link (use at your own risk).

Step 3: Run the vmss2core Tool
vmss2core.exe -N VM-Snapshot1.vmsn VM-Snapshot1.vmem                                                                                                                                                                                    vmss2core version 20800274 Copyright (C) 1998-2022 VMware, Inc. All rights reserved.
Started core writing.
Writing note section header.
Writing 1 memory section headers.
Writing notes.
... 100 MBs written.
... 200 MBs written.
... 300 MBs written.
... 400 MBs written.
... 500 MBs written.
... 600 MBs written.
... 700 MBs written.
... 800 MBs written.
... 900 MBs written.
... 1000 MBs written.
... 1100 MBs written.
... 1200 MBs written.
... 1300 MBs written.
... 1400 MBs written.
... 1500 MBs written.
... 1600 MBs written.
... 1700 MBs written.
... 1800 MBs written.
... 1900 MBs written.
... 2000 MBs written.
Finished writing core.
  • For general use: vmss2core.exe -W [VM_name].vmsn [VM_name].vmem
  • For Windows 8/8.1, Server 2012, 2016, 2019: vmss2core.exe -W8 [VM_name].vmsn [VM_name].vmem
  • For Linux: ./vmss2core-Linux64 -N [VM_name].vmsn [VM_name].vmem Note: Replace [VM_name] with your virtual machine’s name. The flag -W, -W8, or -N corresponds to the guest OS.
#vmss2core.exe
vmss2core version 20800274 Copyright (C) 1998-2022 VMware, Inc. All rights reserved.                                                                                                                                                                            A tool to convert VMware checkpoint state files into formats                                                                                                                                                                                                    that third party debugger tools understand. It can handle both                                                                                                                                                                                                  suspend (.vmss) and snapshot (.vmsn) checkpoint state files                                                                                                                                                                                                     (hereafter referred to as a 'vmss file') as well as both                                                                                                                                                                                                        monolithic and non-monolithic (separate .vmem file) encapsulation                                                                                                                                                                                               of checkpoint state data.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       Usage:                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             GENERAL:  vmss2core [[options] | [-l linuxoffsets options]] \                                                                                                                                                                                                               <vmss file> [<vmem file>]                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        The "-l" option specifies offsets (a stringset) within the                                                                                                                                                                                                      Linux kernel data structures, which is used by -P and -N modes.                                                                                                                                                                                                 It is ignored with other modes. Please use "getlinuxoffsets"                                                                                                                                                                                                    to automatically generate the correct stringset value for your                                                                                                                                                                                                  kernel, see README.txt for additional information.                                                                                                                                                                                                                                                                                                                                                                                                                                                                              Without options one vmss.core<N> per vCPU with linear view of                                                                                                                                                                                                   memory is generated. Other types of core files and output can                                                                                                                                                                                                   be produced with these options:                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    -q      Quiet(er) operation.                                                                                                                                                                                                                                    -M      Create core file with physical memory view (vmss.core).                                                                                                                                                                                                                                                                                                                                                                                                                                                                 -l str  Offset stringset expressed as 0xHEXNUM,0xHEXNUM,... .                                                                                                                                                                                                   -N      Red Hat crash core file for arbitrary Linux version                                                                                                                                                                                                             described by the "-l" option (vmss.core).                                                                                                                                                                                                               -N4     Red Hat crash core file for Linux 2.4 (vmss.core).                                                                                                                                                                                                      -N6     Red Hat crash core file for Linux 2.6 (vmss.core).                                                                                                                                                                                                      -O <x>  Use <x> as the offset of the entrypoint.                                                                                                                                                                                                                -U <i>  Create linear core file for vCPU <i> only.                                                                                                                                                                                                              -P      Print list of processes in Linux VM.                                                                                                                                                                                                                    -P<pid> Create core file for Linux process <pid> (core.<pid>).                                                                                                                                                                                                                                                                                                                                                                                                                                                                  -S      Create core for 64-bit Solaris (vmcore.0, unix.0).                                                                                                                                                                                                              Optionally specify the version: -S112 -S64SYM112                                                                                                                                                                                                                for 11.2.                                                                                                                                                                                                                                               -S32    Create core for 32-bit Solaris (vmcore.0, unix.0).                                                                                                                                                                                                      -S64SYM Create text symbols for 64-bit Solaris (solaris.text).                                                                                                                                                                                                  -S32SYM Create text symbols for 32-bit Solaris (solaris.text).                                                                                                                                                                                                  -W      Create WinDbg file (memory.dmp) with commonly used                                                                                                                                                                                                              build numbers ("2195" for Win32, "6000" for Win64).                                                                                                                                                                                                     -W<num> Create WinDbg file (memory.dmp), with <num> as the                                                                                                                                                                                                              build number (for example: "-W2600").                                                                                                                                                                                                                   -WK     Create a Windows kernel memory only dump file (memory.dmp).                                                                                                                                                                                             -WDDB<num> or -W8DDB<num>                                                                                                                                                                                                                                               Create WinDbg file (memory.dmp), with <num> as the                                                                                                                                                                                                              debugger data block address in hex (for example: "-W12ac34de").                                                                                                                                                                                         -WSCAN  Scan all of memory for Windows debugger data blocks                                                                                                                                                                                                             (instead of just low 256 MB).                                                                                                                                                                                                                           -W8     Generate a memory dump file from a suspended Windows 8 VM.                                                                                                                                                                                              -X32    <mach_kernel> Create core for 32-bit Mac OS.                                                                                                                                                                                                            -X64    <mach_kernel> Create core for 64-bit Mac OS.                                                                                                                                                                                                            -F      Create core for an EFI firmware exception.                                                                                                                                                                                                              -F<adr> Create core for an EFI firmware exception with system context                                                                                                                                                                                                   at the given guest virtual address.                         

Links:

How to Rebuild a VMX File from vmware.log on an ESXi 8 Host via SSH

Introduction

Rebuilding a VMX file from vmware.log in VMware ESXi can be crucial for restoring a virtual machine’s configuration. This guide will walk you through the process using SSH according KB 1023880, but with update for ESXi 8.0. It was necessary add #!/bin/ash because of error “Operation not permitted”.

Step 1: SSH into Your ESXi Host

First, ensure SSH is enabled on your ESXi host. Then, use an SSH client to connect to the host.

Step 2: Navigate to the Virtual Machine’s Directory

Change to the directory where your VM resides. This is usually under /vmfs/volumes/.

cd /vmfs/volumes/name-volume/name-vm

Step 3: Create and Prepare the Script File

Create a new file named vmxrebuild.sh and make it executable:

touch vmxrebuild.sh && chmod +x vmxrebuild.sh

Step 4: Edit the Script File for ESXi 8

Edit the vmxrebuild.sh file using the vi editor:

  1. Run vi vmxrebuild.sh.
  2. Press i to enter insert mode.
  3. Copy and paste the following script (adjust for your ESXi host version).
  4. Press ESC, then type :wq! to save and exit.

Script Content for ESXi 8.0:

#!/bin/ash
VMXFILENAME=$(sed -n 's/^.*Config file: .*\/\(.\+\)$/\1/p' vmware.log)
echo -e "#\041/usr/bin/vmware" > ${VMXFILENAME}
echo '.encoding = "UTF-8"' >> ${VMXFILENAME}
sed -n '/DICT --- CONFIGURATION/,/DICT ---/ s/^.*DICT \+\(.\+\) = \(.\+\)$/\1 = \2/p' vmware.log >> ${VMXFILENAME

Step 5: Run the Script

Execute the script to rebuild the VMX file:

./vmxrebuild.sh

Conclusion

This process extracts the necessary configuration details from the vmware.log file and recreates the VMX file, which is vital for VM configuration. Always back up your VM files before performing such operations.

vCenter Server 8.0 U2 Issue with Edit Settings Virtual Machine Hardware 9 or older

Introduction

I was unable to manage Virtual Machines with virtual Hardware Version 9 or older via the vSphere Client while they are in a powered on state.

Symptoms

  1. vCenter Server Version: The problem is specific to vCenter Server version 8.0 U2 – 22385739.
  2. Virtual Machine Hardware Version: Affected VMs are those with hardware version 9 or below.
  3. VM State: The issue occurs when the Virtual Machine is in a powered-on state.
  4. UI Glitches: In the vSphere Client, when attempting to open the ‘Edit Settings’ for the affected VMs, users notice red exclamation marks next to the Virtual Hardware and VM Options tabs. Additionally, the rest of the window appears empty, hindering any further action.

Impact and Risks:

The primary impact of this issue is a significant management challenge:

  • Users are unable to manage Virtual Machines with Virtual Hardware Version 9 or older through the vSphere Client while they remain powered on. This limitation can affect routine operations, maintenance, and potentially urgent modifications needed for these VMs.

Workarounds:

In the meantime, users can employ either of the following workarounds to manage their older VMs effectively:

  1. Power Off the VM: By powering off the VM, the ‘Edit Settings’ window should function correctly. While this is not ideal for VMs that need to remain operational, it can be a temporary solution for making necessary changes.
  2. Use ESXi Host Client: Alternatively, users can connect directly to the ESXi Host Client to perform the ‘Edit Settings’ operations. This method allows the VM to remain powered on, which is beneficial for critical systems that cannot afford downtime.

Resolution:

Keep an eye on updates from VMware for a permanent resolution to this issue Edit settings window fails to load on Virtual Machines with virtual hardware version 9 or older on vCenter Server 8.0U2 (94979).