Archive for the ‘Windows’ Category

Setup MPIO for EMC VNX Storage

April 23rd, 2015 Comments off

If you use EMC PowerPath, the process is straightforward from EMC. But in most cases, due to the price of EMC PowerPath, we use Microsoft MPIO instead (Which PowerPath uses under the covers)

If using Microsoft’s MPIO, you can use their mpclaim utility from a command line or their GUI for doing all the setup. The following assumes you are using Microsoft MPIO and an EMC VNX storage array. There are only slight variations for other combinations.

  1. Configure hardware for MPIO.
  2. Install Microsoft MPIO.
  3. From a command prompt, issue the command “mpclaim -h” to see the currect storage devices claimed by MS MPIO. With a VNX you should see something like “Vendor 8Product 16″. Looking at the MPIO Devices tab in the GUI will show the same information.
  4. From a command prompt, issue the command “mpclaim -s -d” and you should see that there are no disk present yet, as you haven’t allowed any.
  5. From a command prompt, issue the command “mpclaim -e” to display the vendor product ID string for the connected storage array. Depending on how your VNX is configured, you will see something like this “DGC VRAID”.  There are exactly five (5) spaces after “DGC” and you must have exactly five spaces in the ID.
  6. Now you can add the multipath support for the speicifc IDs you want. Obviously you will want whatever you saw in the previous step, but in case you plan on using some other configurations, you can add everything from the list from above. From a command prompt enter the command “mpclaim -n -i -d “DGC VRAID”. The “-n” switch suppresses the automatic reboot. Repeat that commnd for each all device IDs desired.
  7. Reboot the system.
  8. From a command prompt, issue the command “mpclaim -s -d” and you should see the disks claimed by MPIO on the node. Again, you can use the GUI for all this, too.
  9. Run Disk Management and activate the new disk


Categories: Data Center, Windows

Java Application Error – Security Exception

April 28th, 2014 Comments off

I just updated Java to version 7 update 55 and I can’t login to EMC Navisphere anymore. Java V7u55 just decided to stop the local Java apps without even telling you why. I googled it, most website says you have to add the URL to the “Exception Site List” in the Security tab, but guess what, there is no “Exception Site List” any more.


So you will have to do it the “Old school” way, edit file “exception.sites” and add in the URL at


Note that AppData directory is hidden.


Categories: Data Center, Windows

Group Policy made easy

October 14th, 2013 Comments off

Sometimes I asked the system admins to modify settings of a computer, an user account or a group of servers and I watched them spend hours trying to complete the task. We all know that we should use Group Policy, but the responds I usually get is “I don’t do it often enough”

Well, the process is simple
1. Group the computers, accounts you want change into an OU
2. Create a Group Policy
3. Link the Group Policy to the OU that you created above.

Here how you do it
Step1: Creating an OU and adding in the objects
- Run “dsa.msc” , then create a new OU
- Add the computers and accounts


Step2: Creating a new Group Policy (GPO)
- Run gpmc.msc
- Highlight”Group Policy Objects (GPO)”, right click and select “New”
- Pick a name for the new GPO
- Highlight the new GPO name, right click and click “Edit”



Step3:Link the GPO to the OU
- In “Group Policy Management”, select the OU, right click and select “Link an Existing GPO”


And that’s pretty much it. You will need to restart the client’s computers or run the command

So the updates can be pushed down.

In Group Policy Management, you can also check to see which policies are applied on an OU, and what the settings are of those policies

- Highlight an OU will give you a list of linked GPO

- Double click on a policy will show you the settings

Categories: Software, Windows