Category Archives: Configuration - Page 10

the community is about helping each other: partition table lost and found

Posted by on June 11, 2013 No comments

Hardware:

  • 1 Windows 2008R2 server containing 2 HBAs
  • 2 SAN switches
  • EMC VNX-5100
  • 1 LUN presented over 4 paths (2 per HBA)
  • no PowerPath or MPIO, so Windows host sees 4 vdisks and uses only 1 (with the risk of corruption)

Scenario:

After an unexpected reboot the host lost access to the data on the LUN and it seemed as if the vdisk was unformatted or at least corrupted.

  • I checked the VNX, but all 4 paths were available
  • “diskpart” showed the disk, but no volumes, so Windows people thought it was a “SAN issue” (which it wasn’t, of course)
  • I tried enabling MPIO, but by default this host made the LUN (now visible as 1 vdisk instead of 4) read only
  • After disabling MPIO I installed PowerPath (unlicensed) to be sure Windows only sees 1 vdisk instead of 4
  • After the reboot I once again saw 1 vdisk and PowerPath showed 4 paths (of which 2 unlicensed)
  • Still no luck accessing the data

the Community starts here

And here is where it gets interesting. The strength of the community is where you help each other and in this case the customer called me to inform me that since he had nothing to loose anyway he used “TestDisk by CGSecurity” and this tool actually discovers data patterns on disks and in the blink of an eye NTFS was found and the partition could be restored.

No format and restore of an earlier backup was necessary!

DIP upgrade from EMC VNX 5500 to VNX 5700

Posted by on May 23, 2013 6 comments

Data In Place upgrading an EMC VNX 5500 to VNX 5700

Last week I had the pleasure of being involved in a data in place upgrade of a VNX 5500 that was in desperate need of more capacity and performance. The decision was made to perform a DIP, so this is in fact an easy procedure: replace the Storage Processors and you’re good to go? Well, almost.

Read more »

Fibre Channel Routing: EMC Ask the Expert on ECN

Posted by on April 16, 2013 No comments

Fibre Channel Routing

From Monday April the 15th to May 1st 2013 EMC is hosting yet another “Ask the Expert” discussion on ECN. This time it’s about Fibre Channel Routing.

What is it, what’s it used for and how do you know if you want it?

Take a look at the discussion and join me and my friends Allen Ward and Mr Dynamox on ECN!

And although we close the topic on May 1st, we’ll wrap up LIVE from EMC World in Las Vegas in the EMC Elect corner! So if you’re there from May 6 to May 9, make sure to look out for us. As far as I know the Elect corner will be next to the Blogger’s area, close to the Pavillion.

EMC VNX Replication

Posted by on October 16, 2012 No comments

I want to bring the discussion about “VNX data replication” to your attention. It’s on ECN and the URL is https://community.emc.com/thread/149825. If you want to ask about replication specifically, you can post your questions here or on ECN.

The author, Rupal Rajwar is USPEED certified and works for EMC eServices Customer Support division since 2010.

Performance Calculations on Clariion/VNX

Posted by on August 14, 2012 No comments

Although the actual story I want to point out to you is on the EMC Community Network website (also called ECN), I would like to invite you to join the discussion there:

https://community.emc.com/thread/148025?tstart=0

 

If you’d like to discuss anything here, you’re welcome to do so.

 

Let’s join the discussion!