Wazitech

Ubuntu no init found, Try passing init=bootarg

Frans Van Rooyen — Mon, 21 Nov 2011 22:40:59 +0000

Last week I ran into this problem on one of my Linux VM’s when a host unexpectedly went down. This was on a test system, so I could have just restored the VM but wanted to see what it would take to fix it in case I ever run into it in a live environment, or on a physical host. Here are the steps I took:

Boot from a Live CD, in my case I used Linux Mint since I had a copy laying around.

First I listed my partitions:

ls /dev/sd*

Now just do where sda1 is the partition you would like to fix:

fsck /dev/sda1

This part comes into play if you have LVM partitions, in my case I did. So I had to grab LVM. Make sure you have the networking setup on your Live disk as well as DNS and then do:

sudo apt-get install lvm2

sudo pvscan

sudo vgscan

The last command should list the at least one volume-group

Enable it or the ones you’re interested in

sudo vgchange -a y groupname

Now list the logical volumes

sudo lvscan

Your drive you’re interested in should now appear under /dev/mapper

Now do an fsck on that drive

sudo fsck /dev/mapper/logical-volume

It should see some errors and fix it.

Go ahead and Reboot, make sure to disconnect the Live disk and you should be good to go!

Hardening ESXi 4.1 – Disk Shrinking

Frans Van Rooyen — Mon, 08 Aug 2011 22:38:39 +0000

Coming back from Defcon 19 I was motivated to dig deeper into ESXi security. One of the resources that I found to do this is the VMWare Security Hardening Guide, it is a detailed walk through of hardening recommendations for the Hypervisor from VMWare themselves. Using this manual I wanted to work through each recommendation, understand what the vulnerability is, how to exploit said vulnerability and how to prevent it. So for this blog I am going to start with #1 and work through each one in subsequent blogs and provide the info on how to harden it. So without further ado here goes:

VMX01: Prevent virtual disk shrinking

This was a very interesting one, and I almost skipped over it, thinking that it’s not really a big deal. Here is the rundown of this issue. According to VMWare “Shrinking a virtual disk reclaims unused space in the virtual disk. If there is empty space in the disk, this process reduces the amount of space the virtual disk occupies on the host drive.” The problem: Shrinking these disks repeatedly will cause the disk to become unavailable. Well not really a big deal since you as the admin are in control of this, well that is wrong. Disks can be shrunk from within the virtual machine and can be done by ordinary users or processes. That’s a problem; if you have a terminal server the users on that server can cause a DOS by simply doing a lot of shrinking operations, or a malicious piece of software can also cause your server to die. How hard is it to write something that can automatically do this? Not hard at all, the vmtools on the machine provides everything you need.

What about View? Well it turns out that linked clones, parents of linked clones Shrinking is disabled by default. If you created a Full virtual machine instead of a linked clone and the disk is THICK provisioned the user will be able to cause a DOS on the assigned machine.

So Harding Tip #1: Disable Disk Shrinking for your VM’s

To disable disk shrink for a virtual machine:

Power off the virtual machine. Do not skip this step.
Remove the virtual machine from the inventory.

Edit the virtual machine’s .vmx file and add the following lines:

isolation.tools.diskWiper.disable = “TRUE”
isolation.tools.diskShrink.disable = “TRUE”

So with that we are at the end of Hardening step #1 next; sniffing vMotion traffic.

View 4.6 Events and SQL Express Port issues

Frans Van Rooyen — Thu, 12 May 2011 06:30:55 +0000

I ran across this issue a couple of weeks ago and thought it might be helpful to share the info. I had setup a Express Edition SQL server on a remote server, created the DB and assigned the appropriate security permissions, but when I tried to setup the Event Database, it would not work. I remembered something from the View Install\Config class, that SQL Express port might not be the default port of 1433. I found the following bit on MS:

“By default, the default instance of the Database Engine listens on TCP port 1433. Named instances of the Database Engine and SQL Server Compact Edition are configured for dynamic ports, which means they select an available port when the SQL Server service is started. The SQL Server Browser service helps clients identify the port when they connect.

When configured for dynamic ports, the port used by SQL Server may change each time it is started.”

So if this is your case here is how to fix it:

1. Start > All Programs > Microsoft SQL Server 2005 > Configuration Tools > SQL Server Configuration Manager

2. SQL Server 2005 Network Configuration > Protocols for SQLEXP_INSTANCE

3. TCP/IP > Properties

4. TCP Dynamic Ports

That will do the trick you can now add the SQL Server as your Event Database Server.

Installing VCenter Windows 2008 R2 Prerequisites

Frans Van Rooyen — Thu, 12 May 2011 05:57:14 +0000

Since Windows 2008 R2 is now a 64bit only server, a very good move on Microsoft’s part to transition in only 64bit land, there are a couple of things to make sure gets done before installing vCenter. Particularly two things has to get done to get this install to work:

* Install the .NET 3.5.1 Framework

* Setup a 32bit DSN for vCenter

Install the .NET 3.5.1 Framework

1. Go to Server Manager.

2. Select “Features”

3. Click “Add Features”

4. Expand .NET Framework 3.5.1 Features

5. Select only .NET Framework 3.5.1 (do not select WCF Activation as it will install IIS 7.5 which will cause issues with Apache Tomcat that vCenter will install later.)

Setup a 32bit DSN for vCenter

Vcenter will be looking for a 32bit DSN, so when you get to the part of the install looking for your DSN and you cannot see it, then you have created a 64bit one and need to start over by first creating a 32bit DSN.

1. Download the SQL Server Native Client (sqlncli_x64.msi) from Here. Make sure to download the _x64 version, since you are installing the 32bit client on a 64bit OS.

2. Install

3. Go Start -> Search and type “odbcad32″

4. Create the System DSN

Now you are ready to Install vCenter.