Technology

Understanding Your VMware vSphere Environment

Jeremy Martin, Senior Solutions Architect 

In this week’s blog, we will be covering some basic administrative functions within VMware’s vSphere environment. vSphere has become the gold standard for virtualized environments in commercial, federal, military, edge, and cloud spaces.

Last year, VMware released the latest version of vSphere, vCenter, and vSAN, all of which we will be covering extensively. Just like with any new software revision, vSphere 7 has, as Doug DeMuro would say, “quirks and features”. Our migration to vSphere 7 has mostly been successful and without major incidents. With that said, here are some items to keep an eye out for in your vSphere environment.

vCenter 7.0 Password Recovery

So, you failed to disable the vCenter Appliance Management Interface (VAMI) password expiration, or maybe forgot to change the password before it expired… we’ve all done it; whether we would like to admit it or not is another story. In almost every vCenter deployment, I set up the update repository and backup policy right after configuring the environment. For whatever reason, the password expiration options always skip my mind until I can’t login to do upgrades or reboots. Thankfully, there is a quick and easy way to recover the password for (VAMI), and I will walk you through it on vCenter 7.0.

1. Log into ESXi or vCenter and reboot the vCenter virtual machine.

2. Press “e” at the Photon splash page.

3. Enter rw init=/bin/bash right after “consolebank=0” in the GRUB parameter menu.

4. Press F10 to continue the boot process.
5. Enter “mount -o remount,rw /” when the root prompt comes up, then press enter.

6. Enter “passwd” and press enter in the next line.

7. Enter the new password and confirm it in the next two lines.

8. Enter “umount /” in the next line to unmount the file system in preparation for the reboot.

9. Lastly, enter “reboot -f” to reboot the vCenter appliance. You will be able to login to VAMI with your new password!

10. Success!

vSAN Performance Checks

Have you ever noticed slow vMotion, file transfer, or virtual machine performance in your vSAN cluster? If so, you can check for network degradation through vSAN proactive tests! First, click on your vSAN enabled cluster (1), then navigate to the “Monitor” menu (2), and click on “Proactive Tests” (3). Here you can select (4) then run (5) the Network Performance test, which tests the network throughput between each host in the vSAN cluster.


The “vSAN Hosts and Network Performance Test Results” box will provide you with the bandwidth results from the test. If you see a host with a drastically lower bandwidth, it should be the first area you investigate. During our time with vSAN 7, we’ve correlated reduced vSAN storage performance with a failing SFP module, specifically the one hosting the vSAN service on the VMkernel adapter. Traffic received on ESXi host 2 was only at 6 Kbps! We failed over to our secondary network adapter and reran the network performance test; it jumped back up to 7Gbps. Layer 1 strikes again.

Having a proactive monitoring plan in place is critical in ensuring optimal performance from your vSAN enabled cluster. Too often, administrators think that the vSphere environment is a “set it and forget it” product. Simple daily checks and proper notifications can help mitigate performance issues before they become catastrophic outages.

I hope you’ve found this to be helpful. We know that maintaining modern IT infrastructure can be taxing. If your company could benefit from a more secure, efficient, resilient, and powerful IT infrastructure, reach out to us at info@nextechsol.com. 

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