Luckily, there's a rather easy way to change the forgotten password to something new, and I thought I'll explain how it can be done.

Changing the root password on ESX server

You will need to have access to the serial console of the server which has your ESX installation, or access to keyboard and display attached directly to the same box.

To change the password, we'll follow this procedure:

1) Reboot ESX server.

Unfortunately, if you don't remember your root password, there won't be a clean way to reboot your server. Try to shutdown all the VMs running on it, and then power-cycle the box running ESX.

2) Boot ESX server in single user mode

In this mode, you won't be asked for a root password. When you see the following screen, press the "a" key:

… to change ESX kernel boot parameters. Your screen will look like this:

Now, simply type a space and "single" word, then press Enter:

Eventually, your ESX server will boot and give you a root command line prompt, which means you can do what you want from this moment on:

Assuming you want to change your root password, move on to the next step.

3) Change ESX root password to a new one

Simply type "passwd" and give your new password twice:

sh-2.05b# passwd
Changing password for user root.
New UNIX password:
Retype new UNIX password:
passwd: all authentication tokens updated successfully.

That's it! You have changed the ESX password! Now it's time to reboot the system and allow ESX server to come back up online.

4) Reboot ESX server once again

Type "reboot" and wait for the ESX server to come back online in a few minutes:

sh-2.05# reboot

Are you a seasoned ESX administrator? Do you solve the forgotten root password problem differently? Please share your opinions in the comments section.

See also:

• VMware on Desktop-Virtualization.com
• Official VMware Site

Booting VMware VMs with Windows hangs in VirtualBox

VirtualBox natively supports VMware VMDKs, but so far I was unable to boot any of the Windows XP VMware VMs in VirtualBox – only a few seconds after being turned on, the VM will seemingly hang even though I/O icon in the statusbar of it will indicate some traffic.

Turns out, it's a well known problem, and there's a very simple solution to it explained on the Migrate existing Windows installations to VirtualBox page of the Virtualbox wiki.

Advanced VirtualBox settings: IO APIC

Basically, pre-installed Windows images fail to boot up in VirtualBox because of the HAL (Hardware Abstraction Layer) problems.

There are a few versions of HAL supplied with each Windows:

• Standard HAL
• ACPI HAL
• ACPI HAL with IO APIC support

They are supplied in a form of 3 different DLLs, and only one is picked based on your hardware configuration at the time of a Windows install. Because VMware supports IO APIC in VMs by default, that defines the HAL version used in your Windows VM.

VirtualBox is a bit smarter: IO APIC is disabled by default due to expensive (CPU-wise) virtualization. That's why, by default, your newly created VirtualBox VM will not boot a VMware image with Windows pre-installed.

Still, the IO APIC option is here, so you can just enable it for your VirtualBox VM to make the Windows image work.

This screenshot (click the thumbnail to see it in full resolution) shows what you need to do.

That's it – this trick has really helped me, and I sure hope it helps you. Stay tuned for more VirtualBox tips!

See also:

• VirtualBox – official website
• xVM VirtualBox 1.6
• Sun xVM VirtualBox 1.6.2