Symptoms and error messages for corrupted Hyper-V VHD files are numerous, from the VM refusing to start, to failures to attach the VHD with messages like
"Failed to open attachment 'C:\ directory \MyVHD.vhd'. Error: 'The file or directory is corrupted and unreadable.'”
There are many possible causes why your VHD may become corrupted. It is not necessary to figure out the exact cause if you need it back fast: just restore the VHD from your latest backup, or as Ben Armstrong puts it in his blogpost“Run data recovery tools inside the virtual machine."” As with all things in IT “fast” is a relative term – restoring a 500 GB disk from backup can take hours. Plan accordingly.
If you are going to take the time to investigate the cause, or do not have a backup, then you must “go all forensic”.
No mater what the VHD type, most common causes of data corruption in the VHD (whether fixed or dynamic) are from:
If you can trace back the chain of events leading to the corruption, you will usually find a failure either by disconnecting storage while the virtual drive was being created or moved over the network Note that switching the disk-type from one to the other or expanding the disk may cause the problem, and, for some people, it has solved the problem. Sometimes this failure is not hardware, but caused by 3rd party encryption and anti-virus programs that have been installed on the host.
This Core Team blog post shows one way to begin your analysis.
Fixes to try:
"As always, be vigilant when opening any PDF attachments in unsolicited emails."
Headsup that Symantec today issued a warning of Adobe Reader Zero-day being exploited in the wild. Go smack your users and remind them what happens when you open attachments that drop backdoors on the system.
The new www.answerdesk.com service offers free support 24/7/365 with the option to upgrade to paid support right there if the free session does not suffice. *
*Currently for English-speaking customers, however some Answer Techs do speak other languages, and you can filter/select those ones if you wish.
What’s not to like? This is your get-out-of-tech-support-to-my-friends-and-family-jail-free card! Enjoy
Just sign the paper first
and then pick from the self-service menu:
1. Windows and Office – called “premium software support” ($99/hour if the free session does not work) NOTE: the “latest software": list on the website is Windows 7, Windows Vista, Windows XP, and Office applications (2010, 2007 and 2003).
2. PC optimization (the website does not distinguish or exclude server-class PCs)
3. virus removal and protection
4. one-on-one personal training
You get to select your “answer tech” based on profile information filters, such as their pics, language, service name, number of cases and rating. Curiously, “on line right now” is *not* one of the filter criteria – MSFT – you listening?
From the FAQ (http://www.answerdesk.com/support/faq.s2):
For freee training on Failover Clustering with Hyper-V: Designing a Highly-Available Infrastructure for the Private Cloud
Register here: http://mctreadiness.com/MicrosoftCareerConferenceRegistration.aspx?pid=287
Here's what is covered:
Symon Perriman and Elden Christensen are your presenters. Reccomended.
Did I mention it is free?