VOMA on ESXi 5.1 to find out Metadata Corruption on VMFS

I recently blogged about the how to verify the VMFS Heart beat corruption and in this blog I am going to show you how to use VOMA (vSphere On-disk Metadata Analyzer) to check if there is any inconsistencies after the events such as power outage or some others due to which everything went down at the same time.

voma can be used only on ESXi 5.1 and its not available in any prior version.

You can see the help of the voma command here.

Here are the screen shots of how voma will detect and identify the error found on the VMFS volume

As you can see in these example that there is file used against which the voma command was ran. e.g. .bin

Now before you run the command you may want to take a dump from each affected volume/s and then run the command against the dump file/s.




e.g.


dd if=/vmfs/devices/disks/naa.0000000000000000000000000000:1 of=/tmp/naa.0000000000000000000000000000p1.dmp bs=1M count=1500

voma -m vmfs -f check -d /vmfs/devices/disks/naa.0000000000000000000000000000p1.dmp

Now as you can see the highlighted parts  (with gray background) in the above screen shots which are errors and inconsistencies found on the volumes. The white spaces are names which are hidden due to confidential information. If you find the errors on the volume/s then contact VMware Support for further actions.

There are five phases of the disk analysis and @VMwareStorage (Cormac Hogan) has posted about voma here and here.

You can check out the capabilities of voma on your own on ESXi 5.1.

Help by sharing !!


Thanks for your time.

Windows 2008 Boot issue after extending the disk on vSphere 5

Recently I came across a strange issue on my Lab where I assigned limited size Thick Provisioned VMDK to a W2K8 R2 VM. Just the OS drive.

It was ran out of space and I had to extend the VMDK so did it from the VS Client.

On next reboot I saw that Windows is not booting properly and giving me an error


=============================
File: \Windows\system32\winload.exe


Status: 0xc000000e
=============================

Now I know I still have to extend the partition within the Guest OS but that was the next part I was supposed to do but not even getting that far.

Searching the error at MS site, I found an article to fix the boot sector.

• To do that boot the VM with the Windows OS boot disk
• Select "Repair your computer"
• Open the command prompt, and run:
  
  bootrec.exe /rebuildbcd
  bootrec.exe /fixmbr
  
  (Select Yes for any prompts)
• For changes to take effect, reboot the virtual machine   

VM is up and running after fixing the boot sector so no issue there, but now looking further into the rebuildbcd issue it looks like there is some disk signaturing issue going on but was not able to track it down so still doing further deep dive in to it.

Share this please!!