Resolve RUNDLL error

The below error may come up when you boot up the computer or when you open an application.

Here is how you will solve this.

Go to Start >> Run >> Type Regedit and hit enter.

This will open the windows registry.

Expand: HKEY_CURRENT_USER >> Software >> Microsoft >> Windows >> Current Version >> highlight Run >> Delete the value which includes "rundll" and delete it.

Reboot the machine.

If you do not find this under HKEY_CURRENT_USER try the same location under HKEY_LOCAL_MACHINE.

Let me know if this was helpfull :-)

Kill a process which is hung

Many a time while troubleshooting issues with various applications I have had troubles with services going to a hung state. When the service is in a stopping state you can simply go ahead and kill it from the task manager but what when it is hung at "starting" ? Also not all services run as processes in task manager. For instance, if Exchange POP3 service is stuck in a 'stopping' state. You cant go into task manager and kill the process because its not there. And there isnt a way to force a service to stop in the service manager.

The following commands had been a great help for me.

To kill any process be it hung at "stopping" or "starting" state do the following :-

Open command prompt in elevated mode ie; right click on command prompt and "Run as Administrator".

Enter the following command:
sc queryex (service name)

This will give you the PID(process id) To get the service name, right click on the service under general tab you can see Service Name listed.

Then enter the following command:
taskkill /f /pid (Process id)

Hope you found it usefull.

Note: The process id will keep changing, hence always check the process id before running the taskkill command.

SAN zoning

In any network when a switch is initiated, a connection is established between all devices connected to it. So is in a SAN network. A "Fabric" in a SAN environment is referred to a SAN switch. A network without any restrictions to the storage unit compromises on security, availability and management of storage. This problem can be solved by "Zoning" which is a feauture in fabric switches. Zoning creates rules restrictions as in what FC device can see what other devices connected on the fabric. This is similar to a V-LAN.

Below figure illustrates Zoning on a Fabric.

Types of Zoning

• Hardware zoning.
• Software Zoning.

Hardware Zoning

Fabric port number is used to configure hardware zoning. The physical ports of the fabric are the members. Hardware zoning provides the highest security.

Dissadvantage: Zoning has to be re-configured if the device is connected to a different port.


Software zoning

An HBA card has WWNN(World wide node name) and WWPN(World wide port name). Just like a MAC address goes to ethernet card, WWN goes to HBA card. You don't have to worry about the port on the fabric were the device is connected if it is a software zoning.

For an initiator(servers) WWNN starts with 20:_, WWPN starts with 10:_.
For targets WWNN starts with 50:_.


WWN spoofing

A device can change it's WWN rather using the one given by it's manufacturer. An unknown device can gain trust of a storage device and can access it by spoofing the WWN number.